In no sense do they guarantee this. It would be closer to the mark to say they guaranteed the pat holder would lose money.
Right, that's the purpose from one view. I guess we should consider all views then. Whats the purpose from the patent lawyer's view? :)
Almost all inventions should not be patented. Few are worth it.
That's not a reason to patent tho. You can put your ideas on the web free. A patent is purely a business move.
Regards, NT