My guess is that Kakao is exploiting the fact that, even if it has no grounds to sue Tachiyomi developers, a corporation is far more prepared for a legal battle than a bunch of hobbyists.
I think that this will backfire badly, though. Now they won’t deal with Tachiyomi, but over nine thousand forks.
KS had some impact on me learning Braille. Okay, perhaps not as much as Aldous Huxley saying that it’s comfy to read with your head under blankets, but still.