There's 1001 things that the home secretary 'should' have a deep understanding of, but realistically, someone in such a position has to make decisions all the time in areas where they have relatively little knowledge. (Not that I have any time for Amber Rudd, but this isn't a fair criticism.)
True, but the argument she seems to be making is that she's asking for a change and help from technology companies and they're telling her it can't work that way. Instead of then understanding why (not all the details, just why her option isn't viable) and working with them towards a solution she instead makes comments about them being unwilling to "work with her".
She doesn't have to know how to "roll her own crypto," but if she intends to legislate something like this she definitely needs more than superficial understanding of it. She is trying to "ban math" after all. You don't think she needs to take a little extra time to get a deeper understanding before trying something like that?
How do you get more than superficial understanding? You listen to all parties. Something tells me she's just taking GCHQ's words at face value that terrorists use encryption, therefore encryption must be banned, without weighing other side negatives like increased cyberattacks due to breakable encryption, a harm to people's privacy rights due to GCHQ's very own and well documented abuses, and so on. Something tells me GCHQ isn't going to give her that side of the story.
Also, politicians need to understand that the solution to stopping terrorism can't be just "banning stuff".
Terrorists are now using trucks to drive into people. Should we ban trucks? They will soon send remotely controlled autonomous cars into groups of people. Should we ban cars or even autonomous cars (once millions are already on the road, by the time something like that happens)? And so on.
Plus, what the GCHQ often conveniently "forgets" to tell the public is that they were already warned about the extremists. But they did nothing to stop them?
Why? Well it could've been incompetence, or inability to take action, or simply the fact that there are too many false positives [1] that someone has a certain X percentage chance to do such a crime. Mass surveillance is only going to make that worse not better. So why do they keep pushing for it with the banning of encryption?
They can already do targeted surveillance do against anyone at anytime, no matter their encryption or opsec, considering they've hacked component suppliers such as Gemalto and others. So that's clearly not an issue. It's the mass surveillance they want, and so far we've seen no evidence that it would help them. But we do know it's going to make things a lot worse for the rest of us, in more than one way. So I think she needs to spend a little more time on it compared to the other "1,000 extra things" she needs to decide on.
I think your problem with Amber Rudd is really just that you disagree with her view on how much access the government should have to people's communications. I don't see how any of your points have much to do with how much Amber Rudd knows about encryption. In fact, a lot of your points seem to be on the broader topic of government action in response to terrorism and don't have much to do with encryption at all.
As far as legislation is concerned, remember that there are many many people who work on drafting any given bit of legislation. Amber Rudd would not be doing it by herself.
