I'd love it if anyone could give me a genuine explanation. They are so, so very important to a majority of movie generes, to the point where production would not be able to continue if it were not for them.
They award things such as costume design... What's the actual reason they refuse to acknowledge stunt people and stunt coordinators? Pride?
Especially now that there are a number of awards that are given outside of the main show. It truly wouldn't be that hard.