Sure, with all of the brand new stadiums built in the last few years it's not state-of-the-art like it was in 1964, and because it's no longer new may now be "one of the worst", but I don't see what's wrong with it.
I'd much rather go to Shea than to Yankee Stadium. I think it's easier getting in and out and to and from your seat, and it's considerably more comfortable and roomy inside.