There have also been videos of presentations by firms who work in this area that teach companies how not to hire americans (You can google that). If their really was no advantage to hiring H1-B over a US worker, then why would companies go out of their way to disqualify US workers...?
Seriously? Have you ever actually been in a hiring position?
Hiring people is hard, and risky. Even in jobs where the skill set required is very precise and easily measured, as in engineering, there are all kinds of other random factors that can make or break a new hire (personality, lazyness, ability to co-operate, etc). Companies use every trick in the book to try and reduce this risk, most commonly by tapping employees networks to try and find other people who are known quantities, instead of the random walk-ins you get via normal hiring.
So now you have an open position. Maybe it requires specialised skills. Maybe it doesn't exactly require specialised skills, but there's someone who you just know would be the perfect fit for that position. You know they're capable, creative, etc. Only problem - not an American (and for "American" you can also read "European" for an EU based company, etc).
So what do you do? Obviously the "cannot hire an American to do the same work" standard is absurd, you can always hire an American to do any job, they just won't do it as well as the guy you actually want would. But you have to prove you tried. Hence - gaming of the system. The goal of this process is often not to hire just any H1-B because they're cheaper (they have to be paid the same salary or higher, right?), it's often to hire a specific person and this is especially true at the higher job levels.
The simplest solution would be to eliminate the "cannot hire an X" standard which is unenforceable, unmeasurable garbage anyway. Just ensure the salaries are the same, and, longer term, try and convince people that they don't have some kind of right to a well paid job just because they got lucky in the birth lottery. That other guy who is more qualified but has the wrong coloured skin should have a chance too.