This is a huge problem. Elance has a great system for sorting and a lot more filtering capabilities... Not sure why they would opt for something that doesn't have near the same functionality. Evaluating freelancers is almost impossible with this system.
I saw a similar thread about the search functionality of Upwork, and the basic "reason" that I gathered was that they use an algorithm that allows everyone the opportunity for visibility.
As someone who ranks very high on Elance search I was quite disappointed with this answer. It's good that you're voicing your concerns from the client side! Seems like the search function is very chaotic and has no order to it.