Well, to be fair... Dwarven Weapon Training was created back when dwarves didn't get a bonus to STR... so it was a way to make being one of the martial classes a little more tolerable for them. Humans and dragonborns could take 20s in STR... dwarves could gain proficiency in superior axes/hammers with a bonus to damage. Their attack bonus wouldn't be as good, but their damage would be slightly better.
DWT is more powerful than it needs to be now that dwarves can take the bonus to STR.