They're doing it for money.

They game benchmarks for sales.

They disable windows updates because they can't make USB 3 work with the drivers you get from windows update.

Well the ultimate 'why' is obviously aiming for monetary gain since they are a company, I was referring to a shallower 'why'.

It's cheaper/easier than doing it 'correctly', and no one is applying enough pressure (such as declining sales) to make them change.

This isn't "Hey lets see if we can screw over our users", it's "This shortcut is easy (and I never even considered how it would effect our users)".