The anonymity of the interwebs lets all the monkeys come out and play does it not? Would certain individuals be as "high and mighty" and rude if these were genuine face to face conversations? Nope, I don't think so.
On that same note, this is the internet, what do you expect vato? Instead of asking why or what? Ignore the chatter, put something good out there into the mix, if more individuals on BPL stopped whining and bemoaning the current state of things and instead shared something of quality and substance (ie. experiences, trip reports, newly acquired skills and insight, etc.) perhaps BPL wouldn't come off as foul as it has been of late.
Just my take.