Spies is like Doohan insofar as Spies is the last of his kind.
Steel hardened steel in the golden era of the 500cc two-strokes. Doohan was the last man standing. Spies was the last youngster standing in the twilight of AMA SBK's golden era. Was Mary a problem? I mean, if Uccio can be Rossi's "manager", I'm sure Mary Spies is smart enough to be a manager figurehead.
The yellow cabal might have cost Spies his factory Yamaha seat, but they didn't end his career. I suspect Dorna was the driving factor in Spies jump to satellite Ducati which wasted his talent, and ultimately ended his career.
Dorna view American riders as a sort of affirmative action program to increase the value of TV rights in The States. Naturally, this sort of treatment doesn't foster talent development, and Europeans in the paddock surely whine about handouts for underachieving American riders. Now that MotoAmerica is a Dorna fiefdom, it will probably get worse.
With the exception of Hayden, who did manage to win a world championship, but who also stuck around in GP long after losing a few tenths and half of this confidence, which American rider has benefitted from Dorna's charity? Hayden and Edwards stuck around much too long. Spies' career was ended abruptly by a mediocre ride. Beaubier is nearly 30, Moto2 has wasted the prime of his career, unless he can maintain speed in his early 30s for Yamaha WSBK. Gerloff has hit a ceiling, though it's unclear if Dorna boosted him to WSBK.
In Dorna's defense, they have sent a lot of older world-level talent to the US to help sharpen the field, but the profile of motorcycle racing will need a huge boost to increase the number of groms.