Well 50 years ago people would have gotten attacked/insulted for being Gay significantly more due to culturally differences to nowadays. Then again I didn't live around those times so i may be a bit wrong on that. But I do know being Gay is far more acceptable now, thus people are more willing to ''come out of the closet''/express it through what ever means.
Among women though i know what you mean... it seems quite a few girls go through a 'Bi phase', some are actually Bi of course. Ok I just re-read your last sentence I'm guessing this is a troll post but **** it.. I have already written more then I do in exams... if it's not yh well the above hopefully answers that.
If you really aren't trolling... well put it this way if the last sentence is true western countries would drop in population. As far as i know the population is growing steadily.