First, I have over 1k wins. no 50 of those games aren't with Fiddle, but as a fan of the game, I feel my opinion is completely valid.
I disagree, I think fiddle does exactly what he is meant to. He's a high risk very high reward champ, and because he jungles, and does so with about full HP the whole time, he is an AP-Jungle-Assassin, and he's a lot better at it than people think.
Item dependent? Focusing the high damage dealer is a strategy that everyone uses, fiddle or otherwise, forcing many nukers to buy the hourglass, and ADC's to be really good at kiting, or fail. That's the game you're playing here. That's why the hourglass exists, eventually the nuker will have to take damage from five sources, unless it's just OK for them to be the first dead every fight, we eitehr give every one of them something in their kit to say "nope", or we allow them to build an item. Riot went with the item approche.