Depends how you abuse your car - and I do mean abuse. My car is supercharged and is driven normally ie smooth take-offs, no powershifting, maximum rev full-bore acceleration as and when required. It's only got 7000 miles on the clock but it's had no problem at all although I've got a SPEC Stage 2 and flywheel in the roof for as and when required.
If you do full-bore runs, drop the clutch and powershift, you should expect the clutch to fail because Ford sell you a car not a drag racer and you shouldn't expect them to fund your own brand of motor sport. Just my £1 worth.