For me, buying KSP on console was a no brainer. The only laptop/desktop I have access to can barely run Minecraft, let alone something like KSP. My gaming computer went out years ago, and I don't have the money to fix it. Got the PS4 for Christmas 2 years ago, so that's my main gaming rig. 40$ for a buggy but fun game, that has issues but is still very much playable, versus 500-1200$ for a good gaming computer, PLUS the cost of games. I don't have the cash to drop on a computer.
So I'll settle for an "inferior" system, that has access to games the pc doesn't, and still enjoy myself. I like gaming on pc for mods and random games found on steam, and I like consoles for the other games pc doesn't get, or that have larger communities on consoles.
And besides, KSP on console isn't really that bad. Yes, it runs rough, yes there are bugs, but it's still fun. People forget that not everyone can afford a gaming pc, while consoles are more affordable.