I mentioned it with Zandrax while we watched the Rumble last night and I think it applies for part of the reason Roman get's booed still despite doing pretty good the last few months.
It partially comes down to the lower titles. In the old days you earned the IC Title or some other mid card title before you were ever in the Main Event picture. It was a stepping stone that showed you had something better than the others. They even talk about the IC Title on commentary that way. However, now a days you can show up and completely bypass that and go straight to the main event and challenge for the big title as Roman has done, Ryback has done, Rollins had done (granted he had a briefcase to help), etc. There's no building them there's just we like him he's in the Main Event now.