Punishment and intimidation, no doubt. But, I suspect something even more sinister. Once those of faith are driven from TEC, then they can swell their ranks with secular humanists including a large proportion of homosexual clergy and members. No single demonination currently bills itself as the Homosexual Church, but this seems the direction that they are going, and they certainly don't want to have to start from scratch building congregations and acquiring property.
That may be their hope and intent, but I predict a massive failure. In another arena of my life I encounter (or used to encounter, I don't have as much time for it as I once had) many out-of-the-closet homosexuals and to be honest, they simply aren't looking to be affirmed in their lifestyle by a "mainstream" religion.