Why are classic 4 door sedans "disliked"?
I think it has to do with the same reason the 318 is dismissed and the 340 revered, the factory never really offered a 4 door performance car until the late model Charger. Unless maybe there is a 4 door letter car from Chrysler in the 50's I am unaware of. Either way, at least in America, the 2 door became viewed as a sportier/performance model while the 4 door was more mundane and boring. Doesn't mean that a 4 door with a 426 wasn't a performance car, only that the image wasn't of one.
There generally seems to be some potential drawbacks to a 4 door in a performance model like usually a longer wheel base, heavier overall, sometimes not as well proportioned. Nothing that is all that big of a deal, bur I wonder if it didn't factor into why the factory never offered a 4 door GTX or Roadrunner.
I will add that I hate how the B pillar on a 4 door always seems to be right at my head, so when the window is down the wind seems to be directed right at my ear. Rolling the rear window down helps but not as much as the longer door in a 2 door does since the B pillar is further back. And it's not exactly easy to roll the rear window down when on the road without power windows.
That said, when you are sitting in the seat I don't think you can tell the difference between a 2 door and a 4 door beyond my above complaint. And I have seen plenty of cool 4 doors, and have owned a couple of 4 doors even. I think it's cool when people do a sporty 4 door build, much like using the 318 that is in the car rather than spending stupid money for a 340.