Why doesn't iMovie11 support AVCHD?

Im trying to create a nice movie using clips i took from a trip to New York in october. I used a panasonic camcorder that records in 1080p AVCHD, which inturn is an MTS. format.

This format doesnt seem compatable with iMovie 11.

I cant get to grips with why such a wide spread HD video format cant be used on such a state of the art editing software

Any help guys?

Id rather not buy a different piece of software or a new camera thank you very much

Wammy