It's stupid playing it at Wembley. You 'get to Wembley' as an achievement for reaching the final of a competition, or at least that's what it should be for anyway. The semi's are just another round in the competition, nothing more and nothing less. For it to be played at Wembley is just to help the FA pay back the £1bn they stupidly paid for it to be built. In other words the fans are paying for their fuck up.
Semi's of the FA Cup should always be played at a neutral ground, but not at Wembley. This United tie should have been at St James' Park or somewhere like that, with the final, the glamour tie of the competition, being at the national stadium.