I don't think locked viewmodels in comp matchmaking is that important. In addition, Valve has (through b4nny) explained their reasoning, and even if we don't all agree with it, there is some sense. TF2 needs to be as attractive as possible to potential players when they see it being played, and valve want to make money off skins.
I think a far more important issue with competitive matchmaking is the in-game voice communication. It has unacceptable latency (not even factoring in ping) and the quality is very poor. The latency is especially important.
An example where this is very harmful is a medic being flanked by a scout, his/her pocket doesn't realize. The medic says over voice "Help, scout on me!" But in the time it takes for the pocket to hear that, the scout can take multiple shots, and kill the medic before the pocket fights back if he hits his shots.
Competitive TF2 is (apart from stalemates) very fast paced and fluid, and relies heavily on knowing where your teammates are. The poor quality and latency of in-game voice chat doesn't encourage communication- when your entire team in matchmaking is silent, it's very frustrating because you almost feel like you're playing alone.
So, TF2 team, I hope you're reading this- it would be hugely beneficial to both competitive and casual to improve the quality of voice chat.
And to my fellow players, let's stop focusing on just the one subject of config restrictions. Let's talk about other important issues, like this one.