I wouldn't count the IBM thing because I don't see it as part of the vernacular "big tech" of today; however I do think it's the most evil so far in this thread.
The others? They are mostly aggressive competition, especially the MS stuff, and altogether I don't see them as more evil than Apple's exclusionary UX. What's at the bottom of it for me is that it harms users directly, e.g. what others said about kids getting shamed for having a non-Apple phone. The one thing not mentioned yet that would qualify for me would be Meta's product altogether with its impact on teenagers; and various gambling simulators like Roblox.