I think the term legend when attached to a player depends on what period of time you are lucky or unlucky enough to call 'your era', for me my era was mid-eighties to mid nineties, for my daughters it's 2000 onwards.
As previously stated JJ perhaps isn't the most skilfull player player I have seen in a Wednesday shirt, but he probably is the best they can remember.
However, when at Leicester a few weeks ago my youngest along with her friend, Ellie, were getting autographs from the team as they boarded the bus back home, JJ had a chat and signed autographs, he also promised her his shirt after the Cardiff game.
Obviously she was full of it all week but not wanting to be upset if let down I played it down a bit.
Saturday came and we all know the result of the game, we had to leave on the full time whistle because it was her birthday and we had a meal booked but Ellie went down to the players entrance for some more autographs and low and behold JJ came out with his shirt from the Leicester game, all washed and ironed, asking where Abbey was, Ellie explained the situation and JJ handed over the shirt. She is sat in it now.
So in answer to the OP, yes, JJ is a legend, especially to Abbey and Ellie, they will never forget what he did.
Thanks JJ, Thanks Ellie and thanks Rhys McCabe who did a similar thing for Ellie at Barnsley.