Its legitimately unsafe. Having traffic on one side consistently faster than you and the other side slower greatly reduces the chance of accidents because you can have have some relative assurance that speeding up while merging left is safe and slowing down while merging right is safe. It also keeps faster traffic out of and further away from onramps/offramps.

Drive safe, don't be an asshole, its not that complicated.

There's a saying that I really like that seems relevant here - only break one law at a time.

It’s a great argument actually. Speeding on the highway is generally expected. Going 20 over in front of a cop is unlikely to get you pulled over in most of the U.S. The cops are more than likely doing the same thing. Passing on the right on the other hand is very likely to get you pulled over if a cop sees it. It’s a very dangerous move to pull because it’s not something other drivers can predict that you’ll do. The last thing you want to do is turn a middle or right lane into a passing lane. Then the slower drivers that just want to cruise will be pressured to move, possibly into the left lane which is now no longer a passing lane which compounds the issue, and you just get chaos where different lanes are all going different speeds at random.