That's basically how unlicensed wireless (e.g. 802.11 wireless ethernet) works, and it seems to be working okay. I think increased unlicensed spectrum would be great.

Another option would be to have something like a hybrid of the unlicensed and HAM bands with more liberal output power restrictions than unlicensed spectrum where you have to pass a test and get a proper (inexpensive) license to use the band, but you can do more-or-less whatever you want within the band as long as long as you identify your station, stay within output power limits, and don't intentionally interfere with anyone.