I do agree that you see a lot more trash on the trail coming from Jeep guys, and think it's because of a few factors. There are more Jeeps out there, so if 10% of Jeep owners litter and 10% of Rover owners litter, the Jeep owners will have littered way more. Also Jeep has become a generic term like Kleenex, so if some idiot wants to blow his nose he asks for a kleenex, and if he then wants to go wheeling he asks for a Jeep, so you get more inexperience idiots in Jeeps than Rovers or Internationals, Toys ect.
Stock they seem to perform about the same as a Rover, but the new Jeeps just feel cheap. My buddy has a 2006 Cherokee, and it feels like a POS, everything is plastic and fake inside, my D1 has plenty of plastic iside, but it has pretty decent fit and finish, that's not so-much a knock against Jeep, but American cars in general. A Rubi and D1 cost about the same to mod, sure you can buy some really cheap crap for a Jeep that isn't available for a Rover, but for quality parts it will cost about the same.
What cracks me up are the guys with a tube chassis, chevy powered buggy with Rockwells and a Jeep hood trying to tell me that Jeeps are better than Rovers. The closest thing to a Jeep part they have is a fiberglass body, so how does the fact that a custon rock buggy on 50"s can go places my nearly stock D1 on 32"s can't say anything about the quality of a Jeep?
I don't discriminate against people for driving non Rover trucks offroad, just the idiots who cause trails to get closed. There are a few local Rover guys I don't go wheeling with because they litter, and are disrespectfull to other trail users.
Moral of the story is that all rigs are pretty good stock, but when you start modding them they get better, I much prefer Rovers, but will likley buy a Jeep soon so I can race Jeepspeed class. Like PM said we need to start shooting the idiots who give Rover drivers or Jeep drivers a bad name as littering, drunken assholes.