In 2013 it cost $33,000 to file a software patent: a startup I worked for was trying to file one. There's no way a starving tinkerer would be able to afford a patent.

But assume s/he did afford one.

Now comes the theft. Amazon steals it, and now our tinkerer needs to cough up millions of dollars to go after a one-trillion dollar company. It lingers in courts for decades. Even pro-bono legal advice would eventually give up. Futile.

Patents exist only for companies to wage war for monopolies.