For some reason, the UK government (regardless of parties in power) seems to be fundamentally attracted to autocracy.Theresa May served as Home Secretary for about six years before becoming Prime Minister. Throughout that time, on most days she probably spent several hours just reviewing cases where the police and security services wanted to do something that required explicit authorisation at that level.
It's reasonable to assume that many, even most, of those cases really did relate to the worst in our society. It also seems reasonable to assume that in at least some of those cases someone known to be very bad could not easily be brought to justice through our normal legal processes without undermining some other ongoing investigation. In addition, she was presumably given information and advice primarily by the police and security services, and those same organisations and the officials representing them would be the people either enabled or limited by her decisions.
It isn't hard to see how someone exposed to that pressure for such a sustained period of time would become extremely authoritarian. I don't know how anyone's view of society after such an experience could not be so biased that it would be hard to see what normal life looks like any more. Just about everyone who has become Home Secretary in my adult life has moved in that direction during their time in office.
The only difference here is that by a quirk of political fate Theresa May then became the most senior politician in the UK, with a majority government that gave her the power to drive through almost any legislation if she wanted it strongly enough. She achieved that position without anyone actually voting for that outcome in the first place. Until very recently, she also had little significant opposition to challenge her.
And so here we are, with the Investigatory Powers Act on the books and a government whose most senior representatives don't seem to understand even the basics of modern technologies and their implications yet have little hesitation about proposing regulation or outright bans of some of that same technology if it makes them look strong to enough voters in the week before a general election.