A fantastic example of change that has occured is this thread:
http://www.theyeshivaworld.com/coffeeroom/topic/home-baked-cookies-in-mm
historically if someone was frum you ate their food. Period. now people have developed all sorts of policies and guidelines not to eat outside their house (one poster wrote even water!).
now there may be many possible reason for this shift. whether it is due to a decline in standards, a proliferation of modern technologies that raise many halachic issues that some may rule differently, or a way to show how frum the person is is completely beside the point.
The point is Yidishkeit as practiced today by any segment, is quite different than practiced years ago. This is but another (admittedly minor) example.
Again and I cant stress this enough, the reasons may not be bad reasons. Their certainly are many who might be lax in their kashrus and this new geder of not trusting anyone’s kashrus isnt necessarily a bad innovation. But an innovation it is.