Bought in less than 20% of games by Kayle.
Teemo buys it in just over 10% of games.
Warwick buys it in less than 3% of games after his rework where as before his rework it was basically seen as core.
http://lolalytics.com/champion/Teemo/
Wit's end has been trash since preseason 3 changed it from an item that many fighters/on hit builders would buy to get MR, attack speed and on hit magic damage to an item that costs too much due to the MR stealing resulting on only about 5 champs even being able to consider it since they have enough magic damage in their kits and auto attack a lot.
Shyvana and Udry both buy it less than 5% of the time and have a good ammount of magic damage in their kits if that says anything.
It had a niche back in season 2 of being really strong for the price but not not slot efficient meaing it did not scale the best into late game. Now it is not slot efficient compared to other options for all but a few champs and is not a good item to rush in basically any situation.
And it is always "Kayle and teemo can use it" as the excuse to keep this item as a piece of crap.
This item should by all means be something that Jax wants to buy and Diana after a rework would view as core while Irelia would buy it sometimes. Both Irelia and Jax would get Wit's end in season 2 in a fair number of games. It might of been situational but it was actually worth buying.
Give Kayle and Teemo a revamped Malady that even Azir might like and make wit's end good again for those who actually bought it in season 2.