A priest should be, if not by his bishop, by his conscience. That doesn't always happen. There's a little matter of free will and at this time in history, there are a number of revolutionary priests who are not hard line about this. i think there is some apathy and fear of making waves. There shouldn't be but no one ever said cowards couldn't be priests.
One of the bigger problems we're facing is some very weak bishops who do no teaching. This should be part of their teaching and when bishops like mine do say that politicians who are pro-death are not to take Eucharist (Burke was adament about it), they are labelled as extremist when all they are doing is teaching. Correctly, I might add.
If the bible warning is valid, which I think it is, then the priest who prevents an unworthy communicant is doing that person a huge, eternal favor. Otherwise, the communicants eat and drink damnation to themselves.
Such hard line priests would be showing tough love and demonstrating themselves to be the ones who really cared about the individual.