One of my favorite quotes:

"Politics has nothing to do with what a person personally advocates for." - Norman Finkelstein

An example he often gives is advocating for a world without borders. You can advocate for it, and create a group of like minded peiple and write blogs about it, but it will be like creating a cult. Politics, according to him, starts with what the people want. It has to have some concrete proposals and practical momentum that are accepted (or at least not resisted) by the general public.

I'd argue good policy is a matter of compromise, not conviction.

Maybe I would tend to agree with you in a different context, but here there is no compromise: it is either backdoor communications at mass or encryption.

I agree with all the other points made here around politics; Compromise, check. Realism, check. Popular conviction, check! ... But one simply cannot go up against mathematics armed with wishful thinking.

The reason this is an issue for splitting is that there really are no half-measures. One must choose a path.

The confounding thing about the UK and encryption these past years is that we've had a technically uneducated government and/or advisors that are mischievous. Nowhere have I ever seen the basic humility and falliblism to say;

  "This is a complex issue. We don't really understand the parameters.
   Choosing this or that path could have terrible consequences. What
   do you the people think?"

Of course most will say, the uneducated "people" are the last to have any useful input. At least the elected government have some political chops, if not any technical vision. But we're not asking "the people" to weigh in on the merits of key escrow or weakened PRNGs - the choice is fascism or democracy - because people have a fundamental right to privacy and democracy cannot thrive without that.

You need both. As there are some things you cannot conpromise on. Like. Idk. Things factually impossible. Or Human Rights.