If dropping support for Snowy encourages 20% of Apple's user base to upgrade their hardware then it is a prudent business decision in line with most of the last thirty years of Apple business practice and acumen.
Coming from you, who's so consistently praised Apple's customer support, which has built such a happy, loyal customer base for them, that's a surprising statement, because the policy you're advocating would leave many of those happy, loyal customers feeling like
unhappy captives...most assuredly
not "a prudent business decision".
Inflexible business plans have sunk many successful businesses, and Apple, its market value notwithstanding, is not exempt from history.