A free feat for humans would really be strong, maybe too strong. And as the game is already quite easy, a free feat for any race at level 1 would be surely a problematic feature.
For my taste Human Militia is a very welcomed and strong feature, it especially makes Gale and Wyll so much better. What is debatable is that half elves (my preferred race, but because of visuals actually) also get it although they are already very strong from racial bonuses.
How does it make Wyll or Gale better? They gain proficiency with a bunch of str-based melee weapons which they have poor ability scores for. Unless you re-spec them, Wyll and Gale shouldn't ever rely on a str-based melee weapon to deal damage. Why would you ever waste their whole action to have them make a single melee attack that they will most likely miss anyway?