Why is homosexuality popular?

Why would a guy be expected to be gay if he doesn't have a girl friend, but very few would expect a girl to be lesbian if she doesn't have a boy friend? Why would people think quicker of male than female homosexuality? Why do people talk about gays more than lesbians? Is it so normal for girls to be depicted as lesbian because of their "female" nature (when girls holding hands will be quicker considered as just friends rather than partners)? Why would people rather believe that a single guy is gay than just unlucky with finding a girl friend? Why has male homosexuality become so widely spread, even in societies that originally banned (or still ban) it legally (at least officially)?

Why is it (not) easy for people to decide what they want in life?

Why can some people steadily reach their goals in life, one after another, as if they were born with these goals (like a train moving confidently on the rail track), while others "float" trying to understand what they want (like a boat on a lake)? Why do some people know what they want to be/have in life and others don't? Does it by any chance depend on the upbrining? education (knowledge)? social environment? character?
Which one is better to be - "the train" (going on the rails firmly but with a risk of running off the track in case of a single error) or "the boat" (enjoying the flow but risking to fail in reaching the shore)? Should we feel sorry for the former or the latter?
Generally, do people have to know what they want to reach (have/be) in life?

Why do (not) people marry?

Why do some people marry and some remain single for a long time? When the latter say "afraid of losing their freedom", what do they mean by "freedom"? or do they fear that the relationship in marriage will somehow be worse than just dating/cohabiting? why are they not afraid of staying alone (though still dating from time to time) till their last day? or are they (but still cannot make the right step because of the fear of hearing "No")? Or do they think that living alone is better than having a partner, even when most people in the world prefer to have a partner? (as proved in "Why do people need a partner?")(being afraid of losing their beloved one one day who has been the sense of their life). Or, after all, is it something about them makes other people not want to marry them (too self-centered, not trustworthy, too dominant or too weak)?