KSP1 took 5 years of development to get to 1.0, at a non-software company.
Take-Two then bought the game in 2017 and is responsible for ports and KSP2.
So while KSP1 likely generated returns of Squad-magnitude with a few resources... that doesn't mean KSP2 is capable of generating Take-Two-magnitude returns from a full team.
Dwarf Fortress sold a lot of copies too (finally), but it's also been in development for 21 years!
But their point is for that to even feasibly be an idea to consider, KSP2 would have to be good. It's practically a downgrade from KSP1 in every way except the graphics. Entirely a downgrade if you're willing to install graphics mods in KSP 1.
Dwarf Fortress is an indie game. KSP was an indie game until Take2 bought the game.
The expectations for both these games were low. It was a small team working on both of them so we don't expect much, and since they're indie, they are actually gamers like us and like to play their games.
Being bought by a AAA publisher and having billions at their disposal increases the quality expected by unprecedented levels. And they are just showing that they are even worse than the indie team (HarvesteR) that started KSP. And they have budget and can get more personnel if they want.
I think the graphics of Dwarf fortress and Minecraft are why those games were so much cheaper to develop,
rather than some romantic story about the triumph of the underdog the vs some big bad empire. Turns out fun is more important to some than graphics. There are plenty of people that tried to play Dwarf fortress and gave up because earlier versions were impenetrable.
Of which the consequence should be "Don't turn labors of love into businesses that demands market-leading returns"