By and large, nicely put, Jim.
One item, though, where I feel a need to make a distinction. If you're threatening a reviewer (or a game writer, or a programmer, or... whatever), that's just loathsome behavior, straight up. Don't do it.
But I do think there's some leeway where criticizing a reviewer's stance, even if it might seem to an outsider that you're attacking a reviewer for not having the same view as you do, might not be "entitled" behavior. A professional reviewer is, after all, allegedly doing a job- that job being to provide an informed opinion on a product, an opinion preferably informed and well-supported enough that it can help the consumer in putting together their own opinion and off of that make a choice as to whether the product is right for them.
If the reviewer simply fails to note features or facets that strongly influenced the customer's final opinion on the product, I think they have some right to be aggrieved about that, to feel perhaps that the reviewer hasn't done a very good job. Now as Jim says of the whole, this isn't an absolute; it's possible the customer is getting bent out of shape because the uniforms don't absolutely match the uniforms in the previous episode of the series, or the network play takes a few extra seconds to connect to the servers, or some other niggling point that for them makes the game a "0/10!!!!!!!!" but for the reviewer, and most people who play the game, simply went under the radar because it wasn't that important. But it's also possible the reviewer never played the multiplayer, or wasn't aware that the creators made promises that went unfulfilled, or didn't give heed to a widely-reported bug because they were one of the lucky few who never encountered it. Perhaps that isn't reason to try to destroy them and their career (mistakes happen, we're all human, etc.), but I'm not prone to say it shouldn't be "called out".