The thing is, my brother-in-law was able to afford and renew the patent for it's entire lifetime, until it expired. But he couldn't afford to manufacture it, nor market it properly.
To be honest, he didn't have the knowledge or understanding of these things (he's a heavy equipment operator and one of the best welders I know). He's not the best at math or spelling, but he's smarter and more motivated than many people I have come into contact with. At the same time, he's naive about some things, and a bit unworldly and unaware about others.
If the patent wasn't particularly useful, then why did Toyota and Bell both infringe upon it? For this particular invention, my brother-in-law holds two patents; the second building on the first. His patents build upon, and reference earlier patents that describe similar solutions to the problem at hand, and how his is a better solution, etc.
Now - you may be wondering what kind of device is this - so I'll tell you: It an answer (maybe not a perfect one, of course) to the question of "how do you keep your drinks cold in the summer, and hot in the winter, inside your car?"
His answer was a cupholder designed to be fitted in front of the air-conditioning vents of the automobile. Cold air in the summer from A/C to cool the drink, warm air in the winter from the heater to keep the drink warm. Do you not think that is useful?
Toyota - in the 1980s when my brother-in-law's patent was still valid - made several models of vehicle with a slide-out cupholder in front of the A/C vents which infringes my brother-in-law's patent (it clearly anticipates such a system). I own a 1996 GMC C1500 pickup which has a similar vent-located cupholder (and was sold during the time my BIL's patent was in effect). I'm sure that you've seen similar cupholders as well.
Bell imported and distributed (to Walmart mainly) clip-on cupholders from Chinese manufacturers which essentially were duplicates of the designs in his patents; I still have his original prototype, plus the examples we obtained from Walmart and used in the court proceedings which led to a settlement with Bell.
My brother-in-law never approached either company with an offer - they infringed before he even thought about it; he found out about it after the fact. So - if the patents weren't for a useful product, then why were they infringed upon by at least three (Toyota, Bell, and GMC) separate companies?
Couldn't they have simply sent a letter or something to my BIL to offer to license it instead, and help him as a small-time inventor? Yes - they could have. Instead, they chose the more profitable solution, knowing that the "small guy" wouldn't be able to afford the time or money to fight it.