Kung fu just isn't for sport fighting. It's not even very good for street fighting/SD, unless you're very good at it, which takes years - which most people don't put in.
YouTube is a hotbed of mediocrity at best, so I wouldn't go looking for too much quality there. There is some, but there's so much crap you can't be too sure what you're looking at if you're inexperienced. Plus, you have to deal with a lot of uninformed/stupid opinions that may subtly affect your judgement of a style, performance, demo or fight.
Don't worry about kung fu 'pwning it'. If the style is right for you and you get what you need from it, keep it up. If you spend your time worrying about the credibility of your school, style etc. you're probably in the wrong place.
If you need to feel tough, just go box with someone. Nothing like a few shots to the dome to get your ego in the right place

But seriously man, don't concern yourself with finding evidence that 'kung fu works' or 'rules' or 'kicks a$$'. It only does if you do.