People who want rid of him do realise there is a big trade-off to be considered, right? It isn't as simple as "Eddie doesn't make saves, we can do better, get rid".
Put someone like De Gea in this side and he will make more saves than Eddie. I doubt anyone would argue that. Come a CL Semi or Final, he may make a wonder save that Eddie wouldn't make that wins us the tie. Fantastic, but its one game.
What happens for the other 95% of the season, in those games that Eddie is sat twiddling his thumbs apart from helping us build play? De Gea in these games would be fumbling around, knocking the ball out of play and probably costing us the odd goal with misplaced passes. Not only that, our build up play from the back would have to change completely.
I know we can go out and buy a better shot-stopper but the only keeper I have seen that could come into this side and do an ok job on the football side, and is also a better shot-stopper is Alison and he won't be coming here. Everyone else brings their own problems that I would almost guarantee would have people moaning within a few games.
None of this even takes into account that there are much more pressing needs in this side than replacing the keeper.