I concur. There are a lot of missions that just require bombs on target. If you don’t have to worry about enemy fighters or SAMS then there is no need to put extra stress on an expensive airframe.
That being said:
1. You still need to fly these a lot to keep pilots trained
2. AF planes ARE getting very old. The last B-52 rolled off in 1962 and most of today’s fighters were designed in the late 60s, early 70s. It is a crime that it takes nearly a generation to produce a new fighter.
Any target worth destroying is going to be defended by SAMs and Air to Air support if it hasn't been knocked out by the F-15s.
Much of the blame lies with a Democrat controlled Congress, and with the Clinton administration, failing to properly support the R&D programs. That failure to properly support includes both inadequate funding and poorly defined requirements. The Air Force itself bears some of the blame, as well.