Exploding offers suck
for whom? That's what's missing from that post. They suck
for the disadvantaged party. They're used because they're beneficial to the advantaged party. That blog post is propaganda for YC; it says "Hey, look, the other VCs are gonna try to be mean to you, but we're gonna be REEEEAL nice ;)". They just picked something that they knew was a pet peeve for founders and that they knew wouldn't really cost them substantially to exclude from their courting strategies (as YC already has the best reputation in the business, they don't need exploding offers to get founders to sign up with them). There was probably a list of 5 "X sucks" articles that could've been written and sama just picked the one he felt he could work with best that day. Such pieces should be recognized as the intentionally-placed PR pieces they are, instead of pretending like it's just a random, unvetted musing from the YC president.
sama really wants this deal to go through and he is pulling out all the stops to try to make it happen, including pressuring Jeremy in a way that he's already stated is unfair (though it's unclear how sincerely-held this belief is and how much is just an attempt to court more founders; sama's employment of this technique seems to imply he doesn't really think it's that bad) and then publicly shaming Jeremy to try to get control of the story's narrative and make it "lazy nerd tries to defraud noble investors who push the boundaries of tech" instead of "mega-rich investors won't let a founder get his share of a massive buyout".
Every action is a tradeoff. If I'm being honest, I would probably do a similar thing if I were in sama's shoes, and do everything I could to spin the situation in my favor, since I had already convinced myself that my position was fundamentally correct and that this guy really was trying to rip everyone off. I think most of us would, even if we're not willing to admit it on HN.