> Why aren’t there decent portfolios to look at?
It's a chicken and egg problem. Most clients want to see previous work, but don't want their project to eventually become part of that previous work. The issue is compounded by the fact that most commercial software isn't flashy and easy to demonstrate to the casual observer like, say, a Dribbble account is for designers.
If experience with my own clients has taught me anything, it's that the best way to find good people is to just talk to them. Start incrementally - first a talk, then give them a few days worth or work, then a week, then more. Evaluate them at each step - starting with how they communicate and how professional they are and then the quality of their deliverables. I've noticed a pretty strong correlation between bad communicators and poor quality of work, thought YMMV.
> Lots of time wasted qualifying/disqualify candidates/companies.
Let me put it this way - there are two kinds of freelancers out there:
1. Those that invest in their visibility and charge for it.
2. Those that don't.
They might be equally good developers, but you're going to be paying a premium for the first one since he has intentionally made himself easier to find.