Sadly I'm not old enough to remember if there was ever a golden age of teaching, but I would hope that the automatic go-to stance of parents would be "The teacher knows best" in most situations. However it seems like a lot of the time the go-to attitude is "My child knows best, rather than the trained professional".
On the other hand, by its very nature, Education leaves a mark on everyone who passes through it. People with positive educational experiences will be far less likely to criticize/abuse/undermine/demand to teachers than people who had negative educational experiences - be it a teacher that they hated, they got bad grades, they were bullied and the teachers didn't help, etc etc etc.
Just like medical issues and second guessing your doctor, I think the internet has had a serious impact on many people's stance toward professionals. Forums can be one giant echo chamber of criticism and condemnation, which previously would not have been available, and there's also a lot of false and misleading information freely available that gets stuck in the minds of parents - anti-vaxxers is probably the best example. One single flawed study that is disproven within a matter of months still manages to spawn an entire online/offline movement when 30 years ago absolutely nobody would even have heard of it.
That said, Mums are always going to be protective of children, and always going to be a bit leery about letting someone else look after them for 8 hours a day. If there has been a recent shift, I think it isn't a groundbreaking one. I would hesitate to come down hard on either side of the question.
However to all those parents out there who have criticized teachers, I would suggest walking a mile in their shoes. Try three weeks of 60 hours complete with class sizes of 30+ and paperwork to match, after school and breakfast clubs, 2-3 hours of marking per night to be done at home, and that should do the trick.