MacPorts, formally DarwinPorts, has been around for nine years, and has been post-1.0 for the last six. I am pretty certain that it came out during the Mac OS 10.1 era, and at the time supported down to 10.0.
Given this stark contrast, to compare the compatibility complexity experience of MacPorts to Homebrew with the statement "I've never had a problem" is nothing less than hubris.
Seriously, the history of every package management system (including such stalwarts as RPM, APT, MacPorts, and even rubygems) is the same: they start off with the attitude "why is this so complex" and then get to find out over the next decade exactly why those things are so complex.
Honestly: why does it matter oh so very much to everyone that you have to rebuild a few more packages? Isn't this just a problem of not having binary packages? If so, rather than sit around and build Homebrew, someone should have just contributed some bandwidth back to Fink.