The engine regulations are a problem, a big problem. If a team has a dog of a car, they can spend whatever they have to fix that problem. The engine, no chance. You blew the design, you are stuck with the crappola engine, and that's life.
You think because Coke brought out 'New Coke' that they should be forced to keep it for 5 years before they have any chance of correcting it? No, of course not, they should be able to bring out Coke Classic in a matter of weeks and not lose their shirt. Such a ridiculous business practice would ruin a company, and Red Bull and Lotus are looking at serious issues if they are forced to run a dog engine for 5 years.
Before the stupid Turbo, teams could develop their engines to bring them up to snuff. Some could afford to, and knew how to, others didn't. The dominance of RBR was mostly due to Newey, not an FIA regulation. Even if Newey made a mistake, he could change it right away during testing or during the first couple of races. No chance with the engines.
I don't think RBR should leave the sport over it, but I think FOM/FIA and the teams need to sort out a way to make the engines competitive.