The problem is, there are a few different types of side switchers.
I just realized the free movement of people might offset the effect of spying, in a sense; as it will no longer by spying and just "changing sides" in an instant, really. Surprised I didn't see that before, I have been supporting the previous system in hopes of preserving some level of faction loyalty because it might be propping up the game numbers, but as I mentioned, it really is the crux of this issue. If you stop caring about side switching, you stop caring about loyalty and you stop caring about winning, which makes it more fun.
This is a game at heart, right?