I think you are also forgetting that a decent number of PC gamers today are/were also console games who bought a lot of their games on Xbox Live so buying games off of Steam isn't all that different.

I see. So its Xbox gamers that put us into this? Ironically, its also Xbox gamers that went out of this when the X1 was announced... The big difference here is that XBLN is bundled with any Xbox but Steam isn't and won't be bundled with any Windows device...

No, PC gamers put 'us' into this. Steam isn't successful unless consumers are using it. Perhaps you should accept that your preferred method of getting digital content isn't one that's the majority opinion.

Yeah, but then I still wonder how did PC gamers end us up here. What was the turning point that suddenly made Valve the only choice by the hundred thousands? What did they end up doing that made us where we are now.

Couple of reasons:

1) One of the first to offer PC games digitally (despite growing pains)
2) Reliability
3) Community aspects (believe or not things like the workshop and market are popular)
4) Valve titles allowing gamers to put faith in the platform (Half-Life, Left for Dead, TF2)
5) Competitive sales (not as much as in the past though)
6) Developer support (developers love the Steam platform and not just because of it's DRM aspects. Steam offers devs a wide variety of analytics tools that most other storefronts cannot compete with and it's real time).

Correct, it's the exact same reason why Itunes has grew to what it is now, reliability and convenience. People don't buy the iphone because it's this super duper technological wonder.

So in other words, Facebook + Valve + DRM + iTunes = Steam.
Either way, if their policy is to make buying games easier than piracy, might as well say they failed at that. Because piracy remains easier than buying at all circumstances, whether its Steam, GOG, the store, etc... In the very end, what have we? Pirates playing games earlier than their legal peers in most instances and without online connectivity.

So if I understand, it gradually went up by just adding features, and somehow, it attracted people to it, before it became the only gateway for some games. There was simply no event that made Valve's steaming product suddenly have more people, all they did is they kept supporting it...

To add to this

1 - Not only analytical tools. The Steam frameworks have a lot to offer to developers for deploying their games, not to mention the multiplayer frameworks. Most importantly - it is free to use. That was a brilliant move from Valve.

2 - Steam back-end is completely open to the devs, and they can do what they want. Compare with gOg, which have a very closed back-end.

3 - Valve do not take any cut from Steam keys sold outside Steam. Another brilliant move...

So the developers like Steam, for the most part. Not all, but most do.

Actually, you are wrong... Yes, people still pirate, but it made games more convenient than piracy.

Of course there is still piracy but average PC gamer isn't going that route. The PC gaming market has grew and it's because PC gaming is more 'accessible' than it ever has been. Look at any product ever that mass grew and the reasons are usually the same, accessibility and reliable. How many studies have there been that the average consumer doesn't want to jump though hoops for anything, they just want to purchase their product and use it. For the PC gamer, Steam provides that. You want to know what will kill Steam. It's not some great power outage or bankruptcy or anything like that. It's when it stops being convenient to use and buyers stop using it. It'll be a slow drip instead of a bang at which point some other provider will just step in their place.

On what basis? Pirating a game is as convenient as ever. Google the game name and torrent in the same line, download or magnet link the torrent, click OK, wait until it finishes, install, PLAY. You can delete the torrent client and your browser if you wish to and still be able to play your games. Add to that, the browser is probably built-in and the torrent client is just so damn lightweight, plus the lack of DRM and piracy is already looking more convenient overall and more lucrative than having to buy the game and deal with whatever crap it setup against the user.

Also remember that piracy is even more convenient versus the combo of Steam + Origin + Uplay + Next DRM Client by Next Company.

on the basis that the general customer started using Steam instead of pirating... i.e. Steam is now a success.... so it worked

edit - for most people - piracy is less convenient. You need to find the game, make sure it is not infected, that it is updated, that the crack works, download the game (in what-ever- way). In Steam it is "One-click" --> game ready to play. And it is secure.

All it takes is reading the comments, which show how infected it is, how the crack works, etc, and there are some torrents for the updates. The end result is that with a little extra effort, I get a copy that is the least restricted when compared to forking over $60 bucks for a game that'll be a paperweight once I lose the internet. But hey, that's most people here, and I seriously don't know if humans are getting lazier by the day or if it is just me.

EDIT: Also, that basis has something missing to it. In order to pirate, you get the Steam copy first and then pirate it. And even these legit customers may get back to piracy one day... after they discover they were forked.

good?
maybe, i dont think every gameowner is able to just crack a protection, so they will have to use 3rd parties, with the risk of getting malware , virus , or at least adware on the pc.
So they can easily say go ahead crack it, but its not that simple.
There was a movie character who had a nice slogan, i think it was Stallone in Cobra
something like this or so: just replace Crime by DRM

in the first line, you show yourself how it is less convenient :)

also not forget that "piracy" has several connotations that many not want to be associated with. So when it is more convince, and it works (for the majority, it does work), then it is really nothing to argue with.

You are taking that standpoint that Steam do not work, you keep forgetting that from most people it is working as intended. And the DRM is not intrusive.
Cobra is the cure for DRM?