Why not?
Why call it something that makes sense to everyone instead of something that makes sense to only a few? Everyone knows what a sunbeam is. I haven't played Far Cry 4 yet and didn't know what a "god ray" was until I clicked this thread. I honestly thought it was a some sort of giant stingray I hadn't heard about that was removed from the game. I was excited to learn about a new animal I hadn't heard about before and then immediately felt let down. Some of us don't spend a lot of time admiring Thomas Kinkade paintings, but I digress.
Edit:
Googled it. Now THAT'S a goddamn God Ray.