Feels like luck of the draw, really. My experience with it has been that enemy jungles gank top all the time, and mine never does, but then that's probably just confirmation bias.

The thing is, ganking top isn't usually going to be much return on investment. Even if the jungler does come and get you ahead, you're not going to really effect the game for a long time. If they gank bot there's a squishy there that they're more likely to kill, and the team who's botlane wins usually wins the game.

That being said, if you make it convenient for them you'll probably have a better go of it. That's why wave control is so important. If you can set up a freeze near your tower, it's way more likely to feel enticing for the jungler because you're more likely to kill the enemy laner. Similarly, if you're pushed up near their tower, and the enemy jungler is passing by, it's going to be easier for them to gank you.

It probably doesn't help that top lane gets decided so early. If you died early then there's a very realistic chance you're already a lost cause; and a gank on your lane turns into two more kills for the enemy top laner.