Some companies like Fisker assumed they would get to offer a guranteed 7.5K rebate on every car like Tesla did when they sold their first 400,000 cars or so.

Instead Fisker lost the tax rebate and due to the price war they are going bankrupt fast

Multiple car companies lost out on this tax rebate while Tesla and GM got their tax rebate back.


Other problems with the Zero emissions subsidies
#1 Nothing is truly zero emissions
#2 Hydrogen combustion engines are getting large subsidies to explore a really dumb idea. Gasoline is a better fuel source than hydrogen for combustion engines. Not only is Hydrogen extremely energy intensive to make as a fuel, but then the engine is very inefficient. . . Making the inefficiencies multiply.

Other reason not listed.