You mean as a potential rule? Pointblanking sucks but it should by no means be against the rules. It's just something that inexperienced new players do - it's not like firing out of line or anything where it could be seen as cheating or taking advantage of the "honor" of linebattles.
Linebattles suck when too many gameplay rules are imposed upon the players. NA linebattles already have the no firing out of line rule, which I think is unreasonable enough - no need for more. So yeah, I disagree with that regiment's decision to make point blanking against the rules in their server, but hey, they can do what they want.
I'd say a bad idea, Gives less opertunities for leaders to make plays by close range flanking etc.