The entire US Navy F-14 fleet's entire combat record shows 5 kills, four Libyan ("freedom of the seas" operations in the Gulf of Sidra) and 1 Iraqi helicopter (Desert Storm). Other operations include menacing an Egyptian airliner and diverting it to land at a NATO base in Sicily to arrest a few terrorists. The F-14 occasionally dropped bombs on the Balkans and Iraq as well. (http://en.wikipedia.org/wiki/F-14_Tomcat_operational_history) Clearly, in retrospect you can do just as much--some things even more effectively--with more versatile F/A-18 Hornet or F-35 Lightning II aircraft. And then you have fewer different airframes to service, which is always a logistics boon.

The F-14 was designed to protect US carriers from air attack. They would have been really fucking useful in WWII but since then that job hasn't been necessary. Less flippantly, they may have helped the British in the Falklands, since the Phoenix missile was designed to shoot down cruise missiles like the Exocets which the Argentines used to some success (as well as the planes they were launched from). Of course, the British at the time did not have carriers capable of launching or landing the F-14, only smaller carriers designed to maintain a fleet of Harriers.

Aegis cruisers came out a couple years after the F-14, and do most of the same job with surface to air missiles, and even they are overkill. It's exceedingly rare we will get into a shooting war with a country capable of matching even the F/A-18's performance in the hands of American naval aviators, much less on the high seas. (Off the high seas, it might be useful to have an overpowered air superiority fighter, but that's the F-22's job. Of course, judging from the Iraq war it helps to have as much as your air fleet as possible launching from carriers, just in case you manage to piss off all the countries where the Air Force could base their planes in the region.)

I assume because we're preparing for different threats. The F-14 was designed for creating air superiority in direct confrontations with the Soviet Union. Now our likely opponents will concede that territory to us and respond with suicide bombs.