The site allows the trade to come to you. You are able to look at their reviews and see their ratings to help you make a decision.
This does not mean that you do not need to do your due diligence, but it provides a great starting point.
I posted a project and had a significant number of replies. To be honest, a number of them did not pan out. Some are not as professional as their profile would indicate, but that is why you follow up by asking for references and going out to take a look at past work.
I personally will continue to use Trusted Pros as the basis for my search when I need construction services.