The severe lack of a red side population on Homecoming compared to live is down to two things:
The ability to create red side AT characters blue side
Null the Gull
Before, if you wanted to play a Brute, Corruptor, Dominator, Mastermind, or Stalker, you had to play red side. There was no choice. Now there is. With Null the Gull, people can take ten minute trips red side instead of spending a minimum of a week red side. The combination of the two has effectively gutted red side, at least in comparison to live.