Yes, I find it irritating. YouTube for me is the only outlet for my attraction. I don't want to look for or view child porn because I find the idea of it upsetting, and I don't look at modelling sites because they're illegal here. So I might resort to watching girls doing gymnastics or talking about their make-up. It doesn't fuel a nasty industry of exploitation, nobody is hurt and I can appreciate their beauty with impunity.
However, two things irritate me about the morons who make lewd comments:
1) Those comments may upset the children ('I came to this', 'take your clothes off', etc. ad nauseum).
2) Those comments cannot serve to achieve anything positive - all it'll do is force children off YouTube, heighten hysteria even further and leave those morons looking for other outlets (which may be illegal or harmful, directly or indirectly).
I guess they're just looking to express their attraction, which is something they can 'get off their chest' in real life. It reflects badly on them that they do so by posting lewd comments on kids' videos, but it doesn't reflect particularly well on society either.
Not to downplay the stupidity of the morons who comment (I acknowledge my use of an ad hominem), but I also get irked by the muppets who post the following:
This video is most popular with
Males aged 50-65
Males aged 35-50
Males aged 20-35
Just saying.
Who cares? All this says is that there are a lot of men out there who like looking at little girls. Is this really news to us?
I also get irked by haters in general. A girl of 8 sharing her gymnastics skills online does not need to be harassed by a 12-year-old girl with superior skills: 'you're crap, give up', etc.
Anyway, it's a bit like road rage. The anonymity of the Internet can bring out the worst in people. At base, us humans are a bit s**t, behind the everyday mask we present to the (real) world.