Again Tel, there's a point where, for the sake of keeping the server happy, fun, and active, that RP must be sacrificed for actual in-game play.
Sure...it would probably make AMAZING RP sense for Bretonia to build 3 PoBs at every Jump Hole and Gate that enters New London and then surround it with 6 defense platforms each...making New London basically an impenetrable fortress. But....that would also kill activity entirely.
PoBs that effectively cut off systems, while making sense inRP, kill activity. There's apparently plenty of evidence to support this, and I think there'd be an overwhelming support if you put a poll out there asking if blocking PoBs should be outright illegal. I'd be surprised if there isn't such a poll out there already...given how some like to create them.