Seems like it may be just the luck of the draw. I have only been on SL for about a week. I have been popping in and out of all kinds of environments, intentionally and accidentally - music clubs, new user clubs, beaches, SciFi sims, art galleries, sandboxes, etc. Sometimes I am ignored, and sometimes folks are very nice. I have witnesses a bit of "raunch", but only by willing folks, and none directed at me. Keep exploring. Try "Caledon", very adult (in the way you want), with a lot of information for us newbies.