Simply because the players aren't good enough, thats pretty much it, we have possibly one world class player and that is Ashley Cole i think he's the only player who can realistically be considered as one of the best 2-3 in the world in his position, Rooney may get there, but he's got no chance if he stays in the premier****, hopefully the Glazers will need to pay down some debt and sell him to Barca and then mabye he will develop into a world class striker as at the moment he's not even close.
Sorry but the players are not as good as they or the media think they are, the english players are largely carried by their vastly technically superior foreign counterparts, take Malouda, Ballack, Drogba, Essien, Anelka et all away from Lampard and replace him with English players and he looks poor, take Torres away and replace him with Rooney and Gerrard looks poor (allbeit, significantly better than Rooney)
The media do not help, in the sense that i assume as Capello is a highly successful manager he was well aware like most people that it was pretty obvious that after half an hour of the USA game Rooney was a waste of space and should have been hauled off, but he's in a position where if he had and it didn't work he's have been crucified, Rooney was complete garbage, easily up there as Englands worst player over the tournament, Heskey did more of use in the USA game alone than shrek managed over the entire tournament.
Doesn't mean he's a bad player but he was clearly either unfit or just performing badly, happens to the best but he's been built up by the media to be this undroppable force of nature, we'd have been better off going with Heskey and Defoe for the 3 games following the USA game, but setting out as a 1 man team when your 1 man is playing crap is only going to make him play worse, if Rooney had been dropped after the USA game and then was given half an hour or so at the end of the algeria game i think we could have seen a completely different player, as it was only making him play worse, as he will know better than anyone when he's not performing (hence the outburst after that game) if Rooney had played well and we'd still have lost and the team got the same stick, i highly doubt that he'd have reacted in the same way.