> Whenever this kind of discussion comes up around these parts, you can bet on there being a bunch of people complaining about Brew, but Macports basically never comes up.

Macports comes up all the time, just like you've mentioned it here. It has a few user friendly benefits (no sudo, more up-to-date apps, better gui clients, slightly easier to add custom package, etc), but in general hard to say exactly why one app wins