I think this is the root of it. That the parent comment does the moral equivalence action with "You could easily change that to:" and then inserts startups.
The assertion that I'm rejecting is the mischaracterization of startups. There absolutely are predatory startups, 100%, but to say as-a-group/whole that they're anywhere near the moral equivalence is what I'm rejecting.
Paradoxically, I personally believe that only by accepting this and giving up on trying to steer the conversation or convince anyone of anything can you engage in a way that might accomplish those things. Or at least, for myself personally, I find that when I get too invested my rhetoric gets too heated and I feel all sorts of perverse "someone is wrong on the internet" pressure, and I write dumb stuff that makes people angry but convinces no one of anything.
Whataboutism is necessarily a deflection relying on a stated or implied moral equivalence between something under scrutiny and something irrelevant. Accepting the premise that something is problematic and asking whether that reflects a problem in other places is introducing a new topic of discussion to a conversation. You are free to criticize that, but whataboutism is a mischaracterization.
(And in a strange coincidence, this is the second time I've defined whataboutism tonight, in unrelated threads. https://news.ycombinator.com/item?id=34919705)