I am actually a recovering "newb", having done that godawful GARY thread a few of you may have seen, so I may be able to shed light:
Quite a few of us new guys quickly see all the Gonzo guys posting witty/thoughtful threads, and we grow subconsiously desperate to make our own threads and rake in the peerage.
Unfortunatley, this usually results in us vomiting up the first thing that comes into our heads, so we spew this onto the forum without thinking twice, or once, or at all.
In short, Peer pressure, give people time to learn to doublecheck their stuff and learn about witticisms and sarcasm rather than Teh Oh Em Gee