Theo deRaadt complaining about "copyright theft" is hilarious given his original stance on the ipfilter debacle.
While better than the GPL, version 2 and 3, in the sense that it's shorter, the Apache 2 license is still much more complex than the ISC or the BSD/MIT licenses. Another part of the issue, for some developers at least, is that the Apache 2 license sort of acknowledges that software patents are a thing. So if you disagree that companies should be allowed to patent software, mathematics and processes, you might not pick a license that validates the existence of those patents.
This sounds absurd to me. Software patents don't go away because one stops believing in them. Either the courts enforce them or not.