Head-hopping - within the bounds of convention?

A rant on head-hopping. Is head-hopping within the bounds of convention? 

It's distracting? What if it wasn't so obvious? Would that not be far more confusing? 

I don't mean first-person narratives where the thoughts of another character impose themselves. If a piece shifts from first to third person, that's different. 

You could have a lot of head-hopping in a scene like this.
More broadly, are we entitled to say that a writer is wrong if there is an apparent shift from third-person limited to third-person omniscient, or if a second character comes in halfway through with his or her perspective?

Writers do it well or badly. It's neither poor grammar nor poor writing. And such pet peeves can be seized on by people who don't know any better, to criticise good writing.

People label key events, character motivation, plot points, and voice in ways that make me feel a little stifled, in all honesty.

Maybe Dickens' serialisations might've been assisted with detail of that kind. But I don't feel change of voice should be called out to the extent it is.

Critics might fail me on issues like that. What I mean is they might gimme an F.

But unless it's a first person narrative, I don't see any problem with head-hopping if the writing's strong enough. 

 If a chapter wraps up with a guy alone in a restaurant thinking about his mistress, and then we shift to the mistress's husband sitting outside the restaurant in his car with a gun, and you tell me: "Hey, you just cut away there to another perspective!" you can expect the same rude two-syllable response from me as I give those healthy eaters who say there's too much sugar in pure fruit juice, or who suggest: 

"Rather than pig out on a banana, why not eat an apple?"

Because most of the time these narrative shifts are NOT confusing.

If a reader DECIDES that the novel is a third-person-character driven perspective by Chapter 5, and then sees that it isn't because someone else thinks something suddenly, then that's their problem. I'm happy to read on.