Tibet is a fairly complex issue, with the crux of it being that the british (!?) agreed to 'release' tibet from being a 'satellite' of china (without involvement from china).
The Chinese viewed this as an interference of their sovereignty (I don't think many nations would view it differently had it happen to them).
The Dalai Lhama is someone who represents that same cause (independence of tibet), which is in direct contradiction to China's (unification).
The moral (in)equivalence comes with: Someone is viewed as an 'enemy of the state' and friends/allies are indulging visits from them. China is not threatening military action, it is simply saying it doesn't like this occurring.