Albert Hirschman wrote a famous book called "Exit, Voice, Loyalty" about different styles of responses to conflict. Different strategies are certainly called for in different situations. But most exit strategies (outside of suicide) rely on retreats to spaces outside the sphere of influence of the conflict initiator.
The existential space of the Internet is not the infinite, however. Although a nurturing environment for human freedom, it's also a fragile ecosystem, and giving up on a couple key nodes, in its current form, is enough to destroy it, shadowy dreams of darknets notwithstanding. When freedom retreats from all Internet spaces in the USA, that is plausibly more than enough to kill it as a haven for freedom anywhere.
It's not the end of freedom or anything like that: maybe it's strategic to retreat to spaces more decentralized and harder to compromise than the Internet, and other fights can be fought and won in those. But that's not a gamble I want to make, especially because the fight for Internet freedom hasn't been lost yet! Not by a long shot.
ETA: This came off harsher than I anticipated: I had no idea that Silent Circle is a project of Phil Zimmerman. Damn, that's dispiriting. Time to pop open a beer.
ETA2: Yeah, I think I jumped to conclusions about their central motivation and shouldn't have implicitly doubted as much their stated reasons. Boo me.