There are passive people, less passive people and those who like to take action. I don't really know what the proportions are in any population, but there are many, many many passive people out there. They don't challenge advice they are given by trained medical people, whom we should be able to trust, so looking for an alternative isn't going to be a priority for them.
In our busy lives, we sometimes looks for the path of least resistance, and on diagnosis, being told that they don't need to test, the tablets will reduce BG scores and to continue on a largely unchanged diet must be a comfort, to some people, some of the time.
We are the radical ones. The ones who challenge and seek empirical proof of the changes our professionals expect us to make.
I had a long discussion with my GP, post-diagnosis, by whose own admission would be a danger giving advice on diabetes, and he told me I can be a real challenging patient, and seeing my name on his list always made him sharpen his wits - liking the challenge, but knowing he wasn't in for an easy ride. I quite liked that.