I'd love to gank top lane, but for some reason people think pushing to the enemy tower is a really great way to set up a gank.
Then they don't ward. And the enemy jungler ganks. And, because you're an idiot who's pushed up to their tower with no vision, there's no way in hell I'm going up there to save your ass and give them another free kill.
Then you're under tower, farming because the enemy is ahead. I see a good opportunity to gank, but you just stand there like an idiot, brainlessly CS'ing after I've pinged 3 times and am currently CC'ing the enemy laner. If you were paying attention you'd be able to get a kill, but god forbid you actually do something.
Not saying every top laner is like this, but when 'top needs ganks too' is in my chat log, it's because that person is fucking terrible and/or is feeding, and wants to blame the jungler for his lack of, well, skill. Don't be that guy.
More often than not, top laners that are losing lane are doing so because they're playing badly, not because they're getting camped or their jungler isn't ganking enough. If you're 0/1/0 and still doing the same thing that got you killed, I'm going to gank bot lane and mid because I want to win. I'm not babysitting your ass and giving the enemy jungler complete control over mid and bot lane, as well as dragon control, no sir.
More often than not, top laners that are dominating are doing so without the jungler's help, and when the jungler does come to gank it's only because the enemy top is a walking bag of gold, and motherfucker as a jungler I need gold, Jewbama stole all the gold out my jungle. Thanks Jewbama.
Seriously, PSA to all laners period: If you're behind, your lane isn't warded, and you're pushed up to tower, YOU'RE FUCKING RETARDED! Don't blame your jungler for the enemy being better than Dirt 7 and sending your sorry ass back to fountain to make himself 300g richer, because it ain't his fault.