I agree that the RJ is flown on too long of routes, but that is how the business is now. The mainlines are doing the same thing flying smaller airplanes on longer routes. Now 737s are doing transcons and up to 7 hour flights to South America. The mainlines are flying 757s to Europe. These are 7, 8, 9 hour flights. These use to all be on wide body aircraft, but now they can pay the pilots less and have them fly smaller aircraft on these routes. Also the routes that use to have to be on 3 and 4 engine jets are now on the 777, which pays the pilots less and only requires 2 pilots because of no FE.
This is how the industry is going for now it might go back the other way in the future. Hopefully for all of us it will or we might be flying RJs to Europe.