The root of England's issues this world cup has been down to the senior players not firing properly. Morgan is in awful nick, as is Broad, Anderson's probably bowled 10-15 good overs and Bell's played to his stereotype to an uncanny degree. The other players haven't exactly done well, but you would expect the 4 players mentioned above not only to be getting a lot of our runs and wickets, but also to be leading the team and guiding younger players in tricky situations. They've done none of these things.
Having said that, mindlessly culling them is completely pointless, and breeds a bad atmosphere with everyone feeling like their career could be stopped at any point if someone higher up gives the call. All 4 of these players are top class on their day, but performances have been steadily deteriorating over the last 2-3 years. I'd leave them out of the tour to the west indies in April and get them to join up with their counties for a while but certainly not just forget about them. We need to make it clear that they're not going to be frozen out, and are being left out simply because their form is poor. If they don't improve then we've blooded some youngsters for the future, if they do find some form then we've got a solid core once again.
English cricket is in a dire situation at the moment but snap decisions based on one unexpected loss and a few defeats to very good teams will not solve anything.