You're telling them they'll lose you, but if they did what you recommend, they'd have lost both you and the "quirky creative home user who likes to dabble."
The amateur market creates the professional market 10 years from now. They should make sure quirky home users are using their product, even if they have to pay them to use it. If the quirky instead choose any other tool that is capable enough for professional work, they'll grow into the tool and never leave it. The more that do that, the more the tool will improve to conform to their expectations.
If the quirky start buying Affinity instead of learning Photoshop, Photoshop will be gone. In a hypothetical universe where the choices that were available when you first became professional were either an (even more, by your suggestion) expensive Adobe subscription and buying Affinity, you may never have used Photoshop at all.