There is nothing really startup-specific in the scenario. There are exploitative bosses in all industries and all sizes of company. Someone who's played knifey-spooney before would know this.
I know this post/comment is aging but I feel I have to add my disagreement. Depending on skill and perhaps more than a little luck, navigating your way up to a senior position in the "old school" corporate world can actually be relatively conflict-free. Certainly, exploitative bosses are as widespread as you suggest, but that doesn't mean that every boss is exploitative.