I'm not especially annoyed by this fight, but I do think there's a broader criticism that's reasonable: This manga is gradually shifting to become what it satirizes, and I'm not totally comfortable with that.
I also think some of the flak about "entitlement" and so forth is a really bad direction to go. If you think some specific criticism is unwarranted, fine, but basically saying that nobody should ever be "entitled" to be annoyed by fiction they're reading whose quality is going downhill? That's bizarre. I like reading good things, I don't like reading bad things (according to my taste of what's good and bad). If something starts out bad, then fine, I go read something else. But if something starts out good and I invest time and emotion into the characters and plot and stuff, and then it shifts gears in some way that wrecks that for me, why would I not be annoyed or upset? And why should it be forbidden to say anything about it?
I also have a general problem with the idea that nobody should ever be "entitled" to anything. I know it's a big slogan in the US, but being entitled to nothing seems like a recipe for most people having crappy lives. And even Americans are, in theory, entitled to quite a few things and it would be better if they actually got them: Life, liberty, pursuit of happiness, immunity to unreasonable search and seizure, free speech, democratic government, the beat goes on. Where I come from we're entitled to a bunch of that stuff plus peace, order and good government. People being entitled to things is often good.