Linebacker is one of those positions where seniors tend to get the nod over younger, more talented players. It comes down to things other than athleticism. Being able to read keys and maintain gap integrity. Our defense is predicated on being able to line up and have balance laterally and the upperclassmen are better pre-snap and doing what they have to do post-snap. We do lose athleticism though, because the upperclassmen on the outside aren't very athletic.
I like the group of young players we have though. They are big, athletic, and versatile (Owens, Young, McCray all in this mold as well as freshmen in 2014). In the future, I believe we'll have a more complete group of 'backers, because they'll be bigger and more athletic, but right now, they don't stink, they just lack athleticism to make all of the plays. As is, they are performing much better than they ever have before (Gaines, Cornileus), they just have a ceiling.