All domains should really cost $1000/year from the registrar at a minimum to stop this idiotic "I'll buy thousands of them and sit on them forever until someone offers me enough for one of them to make the whole enterprise worth it".
And parking domains is indistinguishable from using them. Unless under "parking" you mean explicitly stating this domain is for sale. But with imposed restriction squatters will just remove those and park domains with "this domain is... well, you get the idea".
There's issues with what's considered value, but our existing system is nonsense.