Myhill is a brilliant back up goalkeeper for a team like ours, he's easily the best you'll find. Even the likes of Liverpool and Chelsea have what I would say are comfortably weaker back up keepers (Turnbull and Brad Jones, both disasters waiting to happen), Myhill is a decent player who's obviously not as good as Foster but no one who is as good will be happy to sit on our bench!
Goalkeeper is just a position where unless you have a particularly good young player coming through (who will want first team football soon enough) you have to accept there will almost always be a drop off in quality with the backup as obviously there's very little opportunity for the back up keeper compared to other positions. Myhill is a perfectly capable keeper, solid in his performances, I can't recall him actually costing us anything in the games he's played, and he seems happy to be here. He was also apparently excellent for Wales against Ireland the other week (the reason they got a draw) so he comes into our games in something like good form as well.
And as for the poster writing off Daniels after 12 minutes, the mind boggles.