I agree with what you write - that there are lots of people who are stubborn just to be stubborn and lots of people who dont like changing things.
However when we discuss local time and adjusting a local time to the central time, we come to some very different conclusions. For example in Europe, countries from Poland to Spain are in the same timezone. This is very good for business - when you schedule a meeting at 9:00 AM, then it is the same 9:00 AM everywhere (on a side note, never schedule meetings at 9:00, be kind and at least do 9:30).
The problems is that what is good for conducting business is not good for regular people, because due to the "one big time zone" a lot of people live in.. a wrong time-zone.
This is very clear when you look at Spain, where the sun shines after 22:00 (10:00 PM) - while there is no sun when people are supposed to wake up.
At the same time, those in Poland live a miserable life - the sun shines very early, but when you leave work -> there is no more sun (meanwhile Germans have around 1 hour more sun after work, the french 2 hours more sun after work and Spaniards have like 3-4 more hours). Here of course I assumed the 9-5 work (9:00 - 17:00) what is typical for office workers.
The rule is that if you live east from the correct time you are screwed by having less sun. This impacts your quality of life. Imagine you spent your whole life losing 2 hours of sun every day.
I swear I saw research somewhere that showed the same is in USA, those on the western part of a timezone are richer than those on the eastern part as well, what removes the historical reasons from war-torn Europe, impact of communism etc.
As far as I know China has one big time-zone for the whole country. I wonder how it works when the official 7AM is 4AM "sun time" in another part.
In theory people could somehow adjust their hours to the local time, but usually they dont. Offices start at 8:00 or 9:00 AM (and at least more and more allows flexible start or work from home), so those that live east have simply less sun exposure - more miserable life. When sun shines - you are more keen to go outside, for a jog, or whatever. When it is dark? You cannot quantify this easily.