Many small manufacturers or innovators have a product based on a single "ah ha!" moment that took no effort in that moment to think of. They usually took a (potentially deep) background in the field and some luck in having the right thoughts in the right order or being exposed to the right stimulus that day. However, they THEN took tremendous risks in quitting the day job, getting a business loan, building out an office space, setting up tooling, hiring employees, and starting production. The real risk is in that leap of faith that you'll be able to capitalize on your idea and make something out of it. That's what people want some minimal level of protection for. In that sense, your theoretical piezo innovation as a product might qualify.
However, if you just took your idea and ran to the patent office for something to sell to a patent troll... no. There's value there, sure... but it needs to be value that is actively exploited in the economy. If you're just creating land mines to extract money from the marketplace, you're not helping anyone. The goal should be to protect people's investments in creating new things that everyone benefits from.
Very simiar to the patent troll case... I could see how if you're a serial inventor and just sit around coming up with great ideas you should be able to make money selling those ideas to people who will actually bring them to market. It's a tough distinction to make.
The core idea should be competition that is fair. If I spend a year to develop an improvement that takes a competitor one day to copy... that's not fair. If I spent three seconds coming up with a great idea that I know isn't going to be obvious to anyone, so I then spent a huge amount of money and effort to produce the product.... and a factory retools a line overnight to produce the same thing.... that's not fair. However, if someone working in isolation does in three days what some less talented/experienced people did in six months... that's fair. It's nearly impossible to NOT notice the results of your competitor's labors, too. Where do you draw these lines? How arbitrary can this crap get?
I think terms are too long. The current system is pretty crappy. It certainly seems weighted towards the big players. It's a hard problem, though. I don't know what the answers are.