It depends what you see Holy Communion as being for, piglet.
If it's an expression of an understanding and a belief, then any people who are unable to understand or believe the concepts clearly should be excluded.
If it's just an outward sign of belonging to a community then everybody should be included.
If it;s the actual, true body and blood of christ - if anyone actually believes that transubstantiation occurs- then surely to goodness you wouldn't want to impose that on anyone who doesn't believe for whatever reason.
Basically, I think the church are right according to their own rules, stupid according to the hysterical hand wringing rules of the DM, and wrong according to my rules. There's no easy black and white answer here - either it's not true, it's not the body and blood, it's just a social construct so it doesn't matter... or it is true, and it matters hugely that everyone who accesses the host does so with full knowledge of what they're doing.
I know which it is in my parish - social construct all the way. In the one in the OP - well, maybe they have themselves a believer in charge.