Strike UAVs

Probably the most dangerous mission for a pilot is low level strike missions against well protected targets, which can almost be suicide missions which would be inhumane to send a man on. I wonder why hasnt been done more to make remotely/autonomously piloted vehicles do this mission? It crackes me up that people suggest UAVs use as fighters, when in that role sensers and computer intellegence is no where close to matching a human. The tomahawk missle is in a sense a strike UAV, but the problem is its destroyed on the mission. Its just not practicle to use a million dollar a/c that is used once and destroyed, rather than making a larger vehicle that can return and be used again.