Originally Posted by
Nifft
High intelligence is linked to a host of problems, from loneliness (from inability to communicate meaningfully with most people who are ~30 IQ points lower or higher) to madness (from seeing the horrible truth of the universe).
So any ability set with Int 20+ will arguably be bad IRL, especially if you pair it with Cha 8-.
In terms of a class that's bad, 3.5e Fist of the Forest would be pretty awful in a modern, civilized society.
Anything that made you look non-human could be troublesome, too.