As a fill main, I play jng a fair amount. When I'm jungling, and see a gank going down top lane, my thought process generally goes that I have no chance of getting to top lane in time to counter gank (unless im already there, in which case I countergank with joy), so I might as well take advantage of the opportunity by taking his shit in bot lane, or grabbing a free dragon, or ganking bot. Of course, this draws the attention of the midlaner, and bot lane will them devolve into a massive shitfest. So likeliness is that if you get ganked, and your jungler isn't ganking as well, he is probably doing something else equally or more important.
I try to get herald for my toplaner if I do spend a lot of time bot lane, though. See if you can convince your jngler to do that, when they are topside. If they don't, then I would agree that you're getting some awful junglers (ignoring your toplaner trying to get a free objective is a little questionable).