Should that be a synonym, then?
Looking at the questions tagged history, I see a number of questions that should be tagged etymology (probably most of them). However, I don't think all of the history questions belong in etymology, for example:
- Have grammar rules changed through the history of the English language?
- Why did English become a universal language and when?
- What's the origin of Pig Latin?
- Is there a historical trend towards shorter sentences?
These questions are about historical things, but they aren't about words.
Incidentally, I actually disagree with the response in Usage of the "history" tag, that looking at the evolution/origin of a class of words is not etymology; I think it is.
In any case, I guess the question we should ask is if the history tag is useful enough to stand on its own. Clearly, people are using the tag instead of etymology, so there is widespread confusion about the tag. That said, I would not want to see the questions I have listed above to be tagged etymology; that would be flat-out wrong. If history became a synonym for etymology, I fear we might end up with questions like the above getting that tag.