same as it can fail on people with very dark skin. No racism or discrimination needed to explain it

That's a classic case of implicit racism. The technology is tailored to perform optimally against lighter toned skin, because the people building and evaluating the software are all lighter skinned, themselves. Similarly, I'm sure, the developers of the technology didn't bother to evaluate how it would work on people with facial skin conditions, markings, or tattoos.

In classic "Move Fast and Break Things" style, they rushed an application to market that only half worked on some people, and then told anyone who would fail the check by default that this was an individual's problem to resolve.

"Who cares if this system works for ?" shows up in all sorts of lowest-bidder crap work, from medical studies to mechanical engineering. Whether its left-handed car drivers get fucked by a right-hand favorable design or clinical trials that just didn't bother including women as subjects or dark-skinned people failing facial recognition, the implicit bigotry of poor engineering is rampant in our modern world.