Ferguson said: "I think the incentive for every footballer is that one day they can get to a final at Wembley.
"Having the semis at Wembley takes a bit away from the real buzz of getting to the final.
"Given the financial commitment of the FA they couldn't do anything else. And it does obviously broaden the opportunity for more players to have played at Wembley at some time in their career."
The FA insist holding the semis at Wembley is in the best interests of all who take part in the Cup.
A spokesman said: "It has always been part of our business plan to hold semi-finals at Wembley.
"The money generated from the competition is distributed among all the clubs who take part in the competition."
But Ferguson believes it will mean more undue cost to supporters - particularly up north.
United's fans will have to shell out for a trip to London for the Cup semi, if they beat Portsmouth in the last eight today.
And Ferguson said: "That's always another unfortunate part.
"The prices at Wembley are very expensive. London prices are enormous compared with anywhere else in the country.