Roguelikes were first commercially successful back in the 90's
Maybe japanese ones, but not in here. Not really. Rogue (graphical version) and Ragnarok were the only commercial roguelikes anyway, and I wouldn't call them a success in a way much more succesful games were. The reason some developers make commercial versions today is that there are way more players than back then, so everything that attracts some kind of interest will sell ok, I guess? Ok enough to put your game in roguelike genre even it's not a roguelike. That's the problem, sir.
Agreed. I'd even go as far to say that Rogue was a commercial flop and that Rogues main success was the spawning of its genre. The trouble is that for the largest time that genre was freeware, it was for lack of the proper term "donationware" and it was run by a community of freeware/donationware developers who made things in the spirit and nature of Rogue and its ilk for the sake of making things that were like that.
The commercial market however just. Does. Not. Give. A. Single. Flamingo. Pink. Fuck.
The commercial market poisons the well with titles like Risk of Rain, Domina, Hero Siege, Isaac, Spelunky etc and calls those "roguelikes" when they just arent. The commercial market cares more for the cash its titles bring in than how those titles are labelled, and if a title is mislabeled they mangle the label rather than regroup the product.