I don't want to be funny, but I find your argument confusing. You say some people need lawyers because of a failure to understand things, etc, yet you also expect such people to be able to judge whether or not the advice they are getting is good? If they haven't been able to figure it out how do you expect them to figure out which lawyer to listen to?
There is an example below of someone not sure if they are eligible to adjust status under DV. The free legal advice is split, more than one lawyer on each side, between yes and no. How is someone who is confused about the issue to begin with supposed to figure out which lawyer to listen to - given that if they knew the answer to that question they wouldn't need a lawyer in the first place?
http://www.avvo.com/legal-answers/diversity-visa-lottery-751754.html
Also not to be nitpicky, but for blindingly obvious reasons there is no lawyer out there who has 35 years experience with DV cases.