When thinking about this I always assume it is the same reason countries tended not to reach for national security provisions¹ despite how attractive they are, it just isn't clear how to put the genie back in the bottle when you've broken it with the biggest-and-most-crushy hammer you can find.

If you dig around in the other exceptions in the document I've linked you'll see there are multiple places where patent protection and protection of human life are discussed.

I know where I sit on the patent validity continuum already, but I also know other people are furiously bouncing on the other end of that seesaw.

1. https://www.wto.org/english/docs_e/legal_e/gatt47_02_e.htm#a...

Some governments do this.

https://www.nytimes.com/2001/02/19/business/patents-health-e...

Curious about this as well, it would make sense to me for them to do this.