I suspect that the survey is bullshit
Before thinking about survey, you should go to the direct source of how the "prevailing wage" is set - http://www.flcdatacenter.com/O... Then you could see that the "price" has been set. Engineer types get higher wage than Developer and Programmer. Nothing is secret.
Whenever someone talks about H1B, many people would associate it with "Big corporation" or "Cheap labor" which is stereotyping. The intention of the program has been good, but it is abused by big corporations; thus, these coporations give it a bad name. I hope that those who have negative feeling toward the program would open their mind and learn more about what the program really is for rather than close their mind and reject everything about the program.