The quickest flaw in your logic: You're talking about 65,000 / Number of employable American citizens. That's far less than 300 million. Practically, you're talking probably into the 120 million range tops. That still only bumps your number up to .04-.05 percent, but its a start
Next flaw: assuming visas are issued to 'workers' regardless of industry. H1b visas aren't issues to Cambodian rice farming peasants who want to work the drive-though at a Steubenville, OH McDonalds. There are plenty of people with the skills to work drive through jobs, so we don't 'need' to import people for these jobs.
and, as mentioned in other posts, it's only a hard cap per year. The actual number of people working on an H1b visa would appear to be significantly higher than just 65,000. If you we assume that the IT world has a disproportionate number of H1b visa holders, then the numbers start to get to a point where it becomes worth asking the question "Is the H1b visa program really filling a need, or is it being exploited as a way of paying far below market value for employees?"
My own experience involves hearing management say that people 'just aren't available', when the reality is there are plenty of people available. Just not quality, experienced people who are will to work for less-than-helpdesk wages with no benefits.