For some people, ‘w’ and ‘wh’ are 2 different sounds. They differ in the same way that ‘t’ and ‘d’ differ: by voice. Unadorned ‘w’ is voiced, but ‘wh’ is more like a whisper. Which makes that word an onomatopœia. How about that?
It‘s true that for most people, the difference is lost. But there must be 1 person—maybe more—who still pronounce those words differently. So let’s commit to them!
Another reason to do that is that the spellings are so evocative. When you see a word starting ‘wh,’ you know it’s a question. Or a relative. Or something like that. It’s cute. It would be sad to lose it. So the decision is that the English we are respelling is one from before the wine-whine merger. If you can’t hear it, use your imagination. Let’s do it!