Speaking as a Protestant, the principle of having communion without doing harm to oneself or one's congregation is dependent on the following SCRIPTURAL precept:

So then, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord. Everyone ought to examine themselves before they eat of the bread and drink from the cup. For those who eat and drink without discerning the body of Christ eat and drink judgment on themselves. That is why many among you are weak and sick, and a number of you have fallen asleep. But if we were more discerning with regard to ourselves, we would not come under such judgment. Nevertheless, when we are judged in this way by the Lord, we are being disciplined so that we will not be finally condemned with the world. So then, my brothers and sisters, when you gather to eat, you should all eat together. Anyone who is hungry should eat something at home, so that when you meet together it may not result in judgment. (1 Corinthians 11:27-34)

Those of us who maintain "close communion" principles are defending this Biblical tenet. Catholicism only errs insofar as it extended that to include civil punishments as it did during the 1500s when it attempted to murder Luther for disagreeing with its Magisterium.