I just don't see a number next to my character's name as anything meaningful enough to make a difference to how I play the game. I'm enjoying BL2 for the gameplay, the experimentation with skills, the humour and good times with friends in co-op. If I want a feeling of progression re skills and XP I just start a new character. Getting a character to level 50 is a nice little goal to tack onto the experience but I just don't care. With around 100 hours spent in the game all up, with many more to come, I don't think raising the cap to [insert arbitrary number] is going make a difference to my VFM.
This isn't a stand to say that others should feel this way, it's just my perspective and I've yet to see an argument that might sway me to thinking it matters or it should be changed.