For most software companies is a matter of "Get it out the door now, so we can get paid." Spending the time/resources to optimize code doesn't impress people enough to be part of the sales pitch, so it's ignored unless it brings something to a halt.

When I saw software bloat increasing with hardware performance, I assumed there would be cycles of optimization, but it seems that libraries are used more often, not less, and many libraries are super-bloated.

Rushing products to market is the short win. Being able to craft your product well will attract its own attention.