I think the point is that it isn’t really a legitimate criticism of the device. Not having a fingerprint sensor was not a design choice by the keyboard maker. It is a constraint of the operating system that peripheral makers have no ability to work around.

Why bother discussing impossibilities? Might as well criticize it for not being powered by a miniature fusion reactor since that has about the same chances of happening in the short term as a third party Apple compatible fingerprint sensor.

If you want to pile onto Apple instead of the hardware maker, that is valid criticism.