Me either. It was simply too much for Stewart. They were beaten before the first shots were fired, but the Cappies...well, they did what they could.
And if you think about it, old Capellan worlds were the only ones likely to cause real trouble any way. Republican rule is similar to the Commonwealth or Suns, so their populations wouldn't notice a major difference, while long-time Combine planets would follow the directions of their Coordinator and be docile enough to begin with that a flag change is likely to go unnoticed. Heck, maybe even appreciated after a couple of years under a less strict regime. Point being, between Skye's volunteering and the DC's decision to just let go, the Republic had its works cut out for them.
ex-Free Worlds are a coin toss. Some will chafe like Stewart, but others, like those that suffered under the Word or their FWL allies will likely see the Republic as a way to have a greater voice in their future.