Even though I'd push for tabs-for-indentation-spaces-for-alignment, I agree with your sentiment.
The "both"-camp is divided in two groups: the "don't care"-group and the "strict rules"-group (the former probably being much larger).
There was a Stack Overflow developer survey in 2017 which concluded that space users make more than tab/both users. Would be interesting to see the results when accounting for above difference in the both group.
I personally use tabs-for-indentation-spaces-for-alignment in my personal code, but I think I'd lose my mind if I tried to mandate it for a public or team project without a standard code formatter like gofmt.