This is a really good point. Maybe if LL developed partnerships with resident groups, who could each maintain and police a themed welcome area, the situation would improve. They could set it up so that new users could go to a welcome area tailored to their interests.
I was very fortunate - on my first day I more or less got picked up from my welcome area by a nice lady who hooked me up with some decent-looking freebies, answered my questions about how to customise my avatar's look, and made me feel, well, welcome! I wish more people could have that experience.