It's so situational, and aggressive/inconsiderate drivers never seen to think on the details of why people are driving a certain way.

I've only driven through Boston a few times, but I've noticed on the East Coast there are lots of old highways and freeways built before all of the lessons learned and modern practices, so you have things like alternating exits on the left and right of the freeways. So some people need to be in the left lane to exit, and others to the right.

I figure, if you are within 1-2 miles of your exit, go ahead and get in whatever lane you need even if you are going slower, because the alternative is an aggressive merge two minutes later. Likewise, if you are going 5-10 over in the far left and continuously passing relatively dense traffic in the middle lane, I don't think you need to slow down, merge over, and then try and fight your way back just because one guy wants to do 10-20 over.

That said, of the middle lane is mostly open and you camp in the left lane going barely over the limit, that just creates a hazard as people pass to your right.

And this doesn't even touch on HOV lanes in the far left. Like, of in driving with my family and want to be in the HOV, I'll get people who want to go 20 over tailgating me acting like I should leave the HOV lane because it is the far left lane. So I dunno what the etiquette even is in some situations, but some aggressive drivers are just never happy if they can't speed like the highway is their person race track.