Nobody to my knowledge has explained a link, but it is a correlation that has been noted by police, that paedophiles have a greater-than-average tendency to be left-handed than the general population. It's of course not as universal as the correlation with sci-fi, but it's there.
Hahaha! the unusual prevelance of Star Trek memorabilia. Yes I've heard this rumor.
I watched Next Generation avidly while it was in syndication. However, I own zero Star Trek merchandise.