Although, if history bears anything out, automation results in an increase in stupid people, as it makes their lives easier and safer.
And if you want a serious answer: again, assuming it were possible to breed for intelligence, basically breeding idiots out of the gene pool, you would end up with a less diversified gene pool, which is generally a bad thing. The benefits of genetic diversity in a population (e.g. disease resistance - the American Indians weren't wiped out by disease because of a simple "lack of immunity", they were wiped out because Eurasian infectious agents, having evolved to attack a population with a diversified immunological profile developed over hundreds of thousands of years, had a field day in a population with a very limited immunological profile derived from two very limited waves of migration 20k years earlier) greatly outweigh the benefits of breeding for a desired trait.
It's kind of a truism, following from that, that breeding for intelligence would be counter-productive, ultimately resulting in a lack of genetic diversity that would end up breeding more stupid people than smart. It's a statement that can't be backed up by evidence, simply because the evidence - much as for your hypotheses - isn't available, and is overly complex where it is. But as an unscientific statement based on anecdotal evidence, it has the single benefit of being more scientific than your bull sh--.
It always amazes me they don't have more of that happening on the New Jersey Turnpike.