It would be interesting to know, but the problem is, we likely never will know. Valve is incredibly secretive about their practices, and they are never forthcoming with any information regarding their Steam service.
On a more general note, this is one of the reasons I have constantly argued against the Steam service. They are able to impose strict regional restrictions when they want to, regardless of reasons. This is killing the ability for gamers to import certain titles and enjoy them if they have no local publisher support. Now some people are being denied a game entirely. Yet, each day, I read comments about Steam being the savior of PC gaming.
Such a confusing statement when PC gaming is going backwards with more restrictions and publisher control.

I believe it goes both ways.
As Bansama stated already, Japanese publishers tend to avoid PC support in Japan and rarely bother with supporting the platform. They are the likely culprits for many games not being released in the country or delaying release dates till they can get around to it.
However, for other games, I believe Valve has at times interfered with the release of a game or simply not supported it. For what reasons, who knows. As I mentioned, they are not known for their communication skills, and are very secretive about a majority of their actions. It is not exactly the most friendly company/service when it comes to international support.

Why do the japanese publishers dislike the PC so much?

My guess:
SONY
NINTENDO
PCs don't have a Japanese parent company.

Nintendo single handedly saved the console games industry and put Japan completely in charge of it. Every Japanese games manufacturer has followed their lead ever since. It doesn't suit the Japanese games companies to support a platform that's not made in Japan as the console games industry is a large portion of Japan's export. Remember even the original Xbox had a torrid time being taken seriously over there.
At the same time they also have to appeal to foreign markets as Sega's Saturn and Dreamcast proved that domestic success is not good enough for such a huge company. However they would prefer if some of that income returns to Japan which is what happens with PS3 and Wii sales.
Also as Coelocanth points out there is no 'PC' company, and therefore no one to protect the PC's interests. This often means that publishers can say what they like about the format and no-one will put forward a counter-argument to defend it. It must be said that it's not only the Japanese that do this but any company invested in consoles like Epic.

People love big publisher control though, judging by Steam, consoles, Apple and whatever else. They like things being handed to them and someone controlling everything so that they can just log in and play, or put the disc in and play. It's the antithesis of everything PC gaming really is, but Valve are finding huge success in making PC gaming FEEL like that and people are all too eager to give up a lot of what PC gaming is to get that feeling.

The point is mate, I tired that route. All I got was Valve spouting bull shit to both myself and the BBB and nothing changing. It was a complete and utter waste of time and energy.
And if the very developers and publishers themselves can't get Valve to release games on the proper date, what chance do I have? See, there's a point where you just have to give up needing to know why. And I passed that point a long time ago.

I agree. The one argument I see time and time again is the matter of convenience. From my viewpoint, I feel people are truly not aware of the changes that are taking place in trade of that convenience. They are happy to let a company control their lives as you said, but I do not believe people understand what that means. It only becomes clear when the system begins to fail at some point.
So long as the choice remains between retail and online distribution, I am perfectly content going my own way and managing my own games. However, Steam appears to be an unstoppable behemoth, and more and more publishers are forcing consumers to the service regardless. I only wish there were a way to lobby to publishers to keep both options, but I am not sure how that would be possible since those who share my viewpoint are quite the minority it seems.

Steam added ATI drivers update support. I have to admit that despite the flaws steam does an impressive job

I don't really get the big deal with that since Windows, as far as I know, does the same thing. I know whenever I uninstall my video drivers and restart Windows goes apeshit trying to reinstall them.

I can't be arsed to bump up the Civ V thread, so I'll put it here.
New Steam update goes as follows:
Bag open, cats eveyrwhere...

One cannot always belong to a majority. However there are more people outside to share your viewpoint (like me) and I think one shouldn't give up too early. If good games without strict digital control aren't published anymore for some years ... well than its a lost cause but until then I will just refrain from buying this stuff. I don't really need it, its kind of luxury to me.

I must be missing something here. I was under the impression that Steam was just a distribution method, with a few other conveniences like automatic updates. I'm not aware of them rejecting anything on Steam, or doing anything dishonest. They've never given a real answer to the "what if Steam goes belly up?" question, dismissing it saying "it'll never happen". Their forum mods have a horrible habit of not reading too.

I'm sure any company in a monopolistic position in any market is something to be concerned about, and more often than not I am. Steam's just seemed like one which I've never needed to worry about.

Am I missing something here?

Maybe? Usually, concerns about Steam include the DRM part and the privacy. The standard to compare is old style disc check DRM or DRM free like GOG. The differences to the standard that, now, even after date of buying (actaully anytime) your right to play a game can expire and also practically you can be hindered. Before you were only at the merci of your hardware, now also at the merci of another authority. The other difference is that now a client is installed on your computer, that sends and receives data from the internet. E.g. Steam collects usage information. Shouldn't be the case.

However, maybe prices for downloads are cheaper (they aren't still, but maybe in the future) to compensate for this.

Problem: All download only DRM software will need to do these consumer-unfriendly things to some extent.

So, I agree with Kurina. People trade convenience and plain availability (because many games are Steam only nowadays) against privacy and rights. Well, there is a limit for me, if I can't get a certain amount of privacy and rights, I will only buy at reaaaaaaaaaaaaally low prices or not at all.