I suspect the main difference between the US and the UK is simply that in the UK the average citizen is more trusting of their government to do the right thing with any powers it has. That in turn may be because historically the level of abuse in the UK has been lower and abuses that come to light do tend to get challenged and to result in changes in policy.

It's obviously not a perfect world and certainly we do still have some problems with discrimination and wrongful use of powers, but perhaps we are culturally a little more pragmatic about these things than our friends across the pond. Whether that tolerance will one day come back to haunt those who supported stronger government powers if we elect our own Trump is a different question.