The designers played with minions a lot. I think that for most of the playtest lifecycle they had small numbers of hit points.
The designers aren't perfect, but they were considerate enough to playtest this idea for you and didn't like it.
This isn't quite true.
The designers tested giving minions low number of hit points and didn't like the idea that they then had to keep track of hit points for the minions.
His idea is to give minions low number of hit points and if the damage does not meet the threshold, it does zero damage. In this case, there is no keeping track of hit points.