Actually, I'd argue that itch.io has basically no curation.

If you look around itch.io, you will see a lot of games that would not have made it to GOG, including things like game jam submissions, and other games that were made in just a few days. (I believe Celeste Classic, the PICO-8 game that served as the predecessor to the full Celeste release, was made in a matter of days.)

I believe that publishing to itch.io doesn't cost the developer any money, and doesn't even require the game to be looked over.

In fact, I think the only thing resembling "curation" that would go over there is some moderation to delete particularly offensive games (like those that would violate the rules of a forum with reasonable rules, though worth noting that there's no "no politics" rule on that site).

Yep. Not sure with regard to the intrinsic quality of the games when they work as intended, but with with regard to drm, I'd argue that curation on GOG is actually not strict enough.

I don't think games like this one should be sold here anymore:
https://www.gog.com/game/beat_hazard_2

They should have a clause in their contracts that says that if the game suffers from drm-creep or is not updated within a reasonable timeframe relative to other platform, GOG reserves the right to take it off the website.

Good point, had that happen with Ninja Noboken and I was pissed.

It seems as though it would be better for GOG's pipelining problems if their system wasn't set up to encourage devs to submit more than once...

Without derailing this...

A few people have spoken about games released DRM-free on itch.io lacking developer updates / support.

Of the two developers I spoke with, both claimed the Steam version was the most consistently patched and supported.

As to the quality of the games...

Itch.io is -- for the most part -- a lot of games slapped together quickly. Most are more proof-of-concept than complete games. But... there are a few finished, polished, good games there. And in a couple of cases (from my experience), those games are better than similar games here on GOG.

As to GOG's policies...

I've given up ever trying to figure out GOG's policy for accepting a game for sale...

... but...

... if -- as some have claimed -- multiple submissions can sometimes mean ultimate acceptance, it would seem GOG needs to fix that ASAP. If I was a developer who had been rejected by GOG, I would never try again. Why? Firstly, the idea that a second try might succeed in a business environment is claiming the process is broken. Secondly, because I'd see a second try as a waste of time if I could then go to Steam and certainly get more sales with almost no chance of rejection.

I seem to remember reading something written by an itch staffer (I don't remember if it was in the help/FAQ/whatever section, or if it was some other post by a staff member) to the effect that just about anything can be put up on itch, but it won't show up when searching or browsing the site unless it's been manually reviewed and indexed by a staff member (but the dev could still link people to it).

I place itch in the same category as present-day Steam: as a marketplace, not a store. The main differences (aside from size and entrenchment) is that Steam is aggressively commercial and does (last I heard) have a small financial barrier to entry, while itch is a hippie-ish operation which not only requires no up-front payment to list a game, but even allows devs to choose what cut of their sales (after processing fees) they give to itch, with an actual minimum of 0% (again, last I read).

It's a damn shame the itch site has no real account library to speak of -- it's just a list of games you own, but with no way to sort or filter by "recently updated". It's worse by far than GOG in that regard.

Honestly, I prefer Itch over GOG due to the lack of curation. To me, the gatekeeping has simply caused GOG to be less accessible for anyone who had DRM-free aspirations. DRM-free is a cultural thing, and isolationism is a good way to make cultures go into decline.

I will buy Freedom Planet 2 from Itch.