I’m not doubting the facts you mention and the amount of the hypothetical subsidy might be on average in the low two digit dollar range.
The overall point is however that the App Store restriction was known at the time of purchase, so demanding to remove it without compensation is unfair.
(What would you say if your employer or client demands to pay a bit less after signing a contract with you?)
(What would you say if your employer or client demands to pay a bit less after signing a contract with you?)