"No plans for GOG right now, maybe in the future."
https://twitter.com/TommyRefenes/status/1052292130364841984

Super Meat Boy has always been available DRM-free over at Humble Bundle though, still is. So I would guess DRM isn't the issue.

Is 2 years later future enough?
Although yeah, I got their game DRM free years ago.

Nicalis are assholes, I gave up on getting anything from them on GOG a long, long time ago.

Note that Edmund has left Team Meat years ago.

Maybe they don't think the sales from GOG will be worthwhile.

You can vote if you haven't already (and let me know what other games I'm missing):
https://www.gog.com/wishlist/games#search=cave%20st ,
https://www.gog.com/wishlist/games#search=super%20meat ,
https://www.gog.com/wishlist/games#search=isaac&order=votes_total

I wouldn't trust Nicalis to take care of a fish, much less proper game publishing practices.

As for Ed, I have a rather large distaste for his style, game, and ethos. He is exactly the dev you dread to work with because he appears to insist on slowly ruining his games with insane patches, damning gameplay changes, and unfun mechanical tweaks.

Voted and hopeful :D

Well, I think a game like The Binding of Isaac: Rebirth still sells very well (even without discount), but their older released games have already reached their peak. GOG would be profitable for them.

Like most developers, they must think that GOG users' money is worth less than other stores. Their loss. I don't know if it applies to these particular devs, but it seems to me that so many are arrogant and take on this EA-like mentality: "my game is so good that they'll HAVE to come and buy it wherever I deem ok to sell it!". Meanwhile people like me will shrug and buy a GOG game instead.

They probably think that the end result will result in a lower net profit in the long run. It's not like they do it out of spite for GOG or the customers, money is money.

While I think what you're saying is correct in a purely economic sense, I'm not ruling out other motives outside the bounds of economically rational decisionmaking. It just seems fishy to me considering how many games miss the store, that all of those developers would come to the same conclusion about it being a lower net profit long-term (also it appears to me the trend in this business, among others, is to focus on short-term even at the expense of long-term).

Which is frankly bizarre as both of them sell on the Humble Bundle.