These policies, when they exist, tend to be very entrenched in the organization. The legal department will push management to keep them so they can avoid the associated risks.

I would look for another job. While these clauses are relatively common, it's also relatively easy to find employers with less restricting policies. You'll probably have better luck at tech-led companies, in general. I think I've also heard that California's employment law doesn't allow this sort of thing, FWIW.