Truth is he doesnt need to prove anything to you or anyone else. He never said he could win the gps or he is better rider than anyone else. BTW GPs didnt have the best 15 rider in the last 5 years, not even close.
Enjoy his racing in Poland, Sweden and SEC.
FFS just deal with it. He doesnt want to ride there for whatever reason. He doesnt care about history books, if he never wins a GP he is still one of the greatest rider of his era if you cant see that you are blind.
It would be good for german speedway. Dont say he is not good enough he already won a GP event, many riders who raced for years in the GP couldnt do that.
An he is kind of a character what GP really lacks, apart from NP there is a personality vacuum in the GP series.