Just because you dont know how to play a champion is a "not fun" champion for you?
That isn't the only reason.
There are styles of champions I like and styles I don't like. One of the things I hate is a missed kill or those people that get away. With almost any champion this can happen. It doesn't happen with Yi because he has a super high base speed and speed improving skills. I like Jayce because of his poke and speed. I like Malzahar because of his combo and because of his poke. I like Mundo because it is fun to just walk around and hit people with cleavers.
And I like how you assume that I am ruining the game for people because of the way I play Yi. And how I am blaming losing on other lanes when it is really my fault.
Firstly, if it is such a bad strategy then matchmaking will put me with people who suck just as much. So I am not ruining anyone's experience. Most importantly, jungle Yi is a valid strategy and I try to gank as much as possible without losing out on jungling. It isn't my fault if I say, "Coming bot to gank." and then the bot lane pushes the foes into their turret so I can't possibly do anything. If anything, they are the ones ruining my game by wasting jungle time with their sucky coordination.
I usually play with my friend who has over 1000 wins and he usually invites a few others with just as many wins. I have only received positive feedback from my allies. For perspective, I just reached 100 normal wins.
The main reason I think this is a viable role is because I haven't even gotten good with it yet and manage to do good enough to get 4 consecutive normals wins with it.