It's not absurd. Just because it's available somewhere doesn't mean it's easy to find. Also you're having your arm twisted to purchase something that will probably be used very little elsewhere in your life. Why not just use the more common screw and make things a bit easier?!

It's almost like a company using an uncommon electrical plug on their power cable, and expecting everyone to buy an adapter to use it. People would be outraged.

My decking was installed with a somewhat uncommon drill bit that isn’t in many people’s household toolkits. Is my decking user hostile?

If there is a valid mechanical/electrical/physical reason why they would choose one fixing over the other, then fair enough - sometimes the more esoteric product can be the correct or only one for the job. If they're just doing it for the sake of making it harder to work with, then, by definition, it's user hostile.

What screw head did they use?

Square. You won’t find square bits in any supermarket or gas station store. But they’re readily available in hardware stores.

Similarly, the screwdriver bits needed to open a MacBook are readily available from computer repair parts stores.

Seems perfectly analogous to me.

Those are Robertson-bit screws, and are ubiquitous here in Canada. (Also a Canadian invention, don'tcha know.) https://www.robertsonscrew.com/

They work great with a power driver, such as you'd want for putting in a deck or fence, so 2-3" deck screws are like my version of duct tape around the house.

It’s just a small star shaped screw IIRC but nothing specific to Apple; other small electronics use these too.

BTW, I wish manufacturers would stop using Philips screws. Hex or Torx is so much better design.

Depends on the application, Torx doesn't cam out for example which in some cases could be undesirable.

I don't see why cam out should be ever desirable. Use torque wrench if necessary. Meanwhile, with Philips this turns out: screw is fastened with cam out torque ... some time later ... due to dirt, rust, etc. it now requires slightly more torque to unfasten, but that is higher than cam out! So now you have to wrestle to push driver stronger, each failed attempt wears screw more, and of course you can hurt yourself when it cams out when pushing strongly.

I agree that cam out is not usually desirable, however it could be used as a safety mechanism against excessive torque for the material being screwed into (although it's probably not the best way to implement a safety measure).