I feel that this logic is faulty. The reason being if the libinput author hasn't already done this over the past near decade Mac has been trashing competition with their touchpad, it's more likely that they don't know how (or don't care about) implementing that support.

The reason for this is they've presumably implemented plenty of other stuff without being paid to. There's no information given so far to suggest otherwise.

Absolutely no insult to that author though. They are entitled to choose to work on whatever they care about.