If a piece of important or foundational software wants to lock itself down today, look at the myriad of convoluted "solutions" mentioned in a sibling comment. If you wanted to discourage progress in this area, that's how you'd design something. I'm not assuming malice, obviously, but it's certainly a product of the endless nitpicking and "not good enough, doesn't cover <niche usecase>" type of thinking.

EDIT:

> and the ones that do will likely be lazy

I'd argue the opposite, any developer taking the time to add some pledge calls to their code is probably mindful of security and wants to improve it. If you wanted to be lazy, you'd just... not implement pledge at all since it'd get in your way and be too restrictive.