- Liverpool made a request not to play on the 14th April because it's the anniversary of a tragedy which profoundly affected a whole city.
- Chelsea doesn't want to play on the 14th because they want to have one extra day to rest ahead of a match they are not even scheduled to play yet. Furthermore, at the time Liverpool made the request, Chelsea were not even qualified to play the FA semis.
By agreeing to the first request the FA hasn't given any sporting advantage to any of the teams concerned and hasn't created a bad precedent since the reason behind the request is far from being a frivolous one - like the death of Roman's mother as someone has suggested.
Wishing to have one extra rest day should never be a valid reason for a game to be scheduled on a particular date. This would create a bad precedent and would open the doors to all sorts of frivolous demands which the footballing authorities would find hard to entertain.