I would argue that some completely separate (sourced) books in a fancy web-giftshop doesn't constitute a product alternative or range-extension.
It's almost akin to a successful tech company starting an annual conference — you wouldn't lambast them for 'losing product focus' on spending a similar amount of productivity (as a book line) in a non-tech-stack branch, would you?
Now, if they doubled-down on Stripe Press to the detriment of Stripe the service, then they would indeed be making a silly mistake. :)
It's almost akin to a successful tech company starting an annual conference — you wouldn't lambast them for 'losing product focus' on spending a similar amount of productivity (as a book line) in a non-tech-stack branch, would you?
Now, if they doubled-down on Stripe Press to the detriment of Stripe the service, then they would indeed be making a silly mistake. :)