I get the decision though.
To be totally fair in punishment they'd have to prove the riders were included in the cheat.
If they can prove that the riders knew the valves were changed then they could be penalized. However, if the situation is more like Management and Engineers telling the riders; "Don't worry about revving it, everything will be fine" then I don't see how a rider can be punished.
They can punish the riders just the same, but fairness to the team riders has nothing to do with it. The fairness comes into play with other teams. I'm sure Suzuki and Ducati have an opinion about it... Regardless, Yamaha chose to bypass the MSMA regarding the sealed parts exception to the homologation... that's provided for in the regs here:
b)Exceptions can be made for sealed parts that are solely associatedwith safety issues and which have no performance benefit, which
may be changed during the approval period with the unanimous
consent of the MSMA MotoGP Commission. Such exceptions will
be on a strictly limited basis to correct a proven problem which
may have safety implications (eg. a faulty batch of parts, with
supporting documentation from the parts supplier to identify
the problem). Engines already sealed, including used engines
can be updated in this way with the unanimous consent of the
MSMA MotoGP Commission and under supervision of the MotoGP
Technical Director or his staff. If a competitor intends to modify
the approved engine in this way he must provide precise details
of the planned changes to the MSMA MotoGP Commission. In each
case, only the approved changes may be made.
If what Yamaha was saying is true, with faulty valves or whatever, the exception is clearly spelled out.
As the press release clearly says they bypassed the MSMA commission process (
https://mcusercontent.com/828d05dc5...amaha_Motor_Company_Protocol_Infringement.pdf), perhaps what the stewards are saying is, "Had you followed the process we would've OK'd the change," therefore, they won't punish the riders.
It appears they simply failed (probably intentionally) to comply with the process and are being punished solely for the breach of protocol. Maybe it was better to ask forgiveness than permission (as who knows how long the exception process takes), sacrificing the constructor's points for a Yamaha rider's championship, especially while MM is sidelined.