After doing the quests for the zones on my Alt (still have a few wanted) and invasions, emissary, war campaign I only need about 10K more rep that is required to grind. The amount will very based on how long it takes you to do the quests and how many emissary and invasions fit in. My alt still has less then 2 days of /play time. The bad part really doesn't come into play until you hit the 12k into revered mark.
They could make it a non-issue if the rep from invasions is given in tokens rather then just 7th legion or Honorbound. I've already hit two paragon rewards with them. It isn't that bad of a thing to unlock them currently and is relatively easy to get by playing the game naturally. Isn't that the point of wanting to unlock the allied race though? Playing the game. You don't get anything special at end game for an allied race. So it isn't a big deal if you don't want to do content to unlock them if you wouldn't be doing that content anyways.