" What you're describing for patents is not violating patent law"
The law says I can't reproduce what's in a patent without permission/license from the patent-holder. The law also says that your intent doesn't matter: unknowingly infringing is also a violation but with less penalties. The big players defining markets or entering mature ones file patents on as much of them as possible to maximize chance new competition will infringe on one of their claims. They also acquire companies for their patents. So, newcomers often have to violate patent law or pay some large amount to a bunch of companies just to get their product in the market if keeping it legal.
Or they just build, grab market share, and pretend patents don't exist. That's how almost all of them make it. The alternative is endlessly Googling patent databases about almost everything your business is doing in tech. I say good luck to a startup or SME trying to do that.
"You have an unusual set of ethics there."
The above advice was given to me by people who create patents for big companies. They said it's what their employers do. It's not my ethics so much as the only option that works without putting one player in a defensive, weak situation. That player still might get hit by NPE's, though. Whatever isn't deterred will involve a big payout to patent-holder or a bigger payout to lawyers that, if defense fails, results in an even bigger payout to patent holder.
"I doubt you'd find many people in the tech industry who would equate potentially infringing someone's patent to adopting source code you don't own into your product in a copyright-infringing way."
In their minds, that might be true. It wouldn't surprise me given that patent provisions aren't in a number of FOSS licenses. In legal reality, they're both a monopoly on a something that require a license to legally use. Thanks to bribery of politicians, the game is also rigged in favor of patent-holders and big incumbents most of the time.