Theresa May and Jeremy Corbyn have a lot in common. As well as both wearing blinkers 24 hours a day, neither has probably really changed their mind on anything significant, ever. Hence the total complete mess the country is in, which can only get worse!
I completely agree - sadly we live in a world where people take a stubborn refusal to adapt your thinking as a Badge Of Honour, people confuse ignorance with "authenticity".
For example, in Corbyn's case, I'd have agreed with him a generation ago that railway privatisation was A Bad Thing. But as we learn more about it, I've come to accept that things like nationalisation/privatisation/ ownership are just means to an end, and the more important thing is how well the structure delivers a good railway (e.g. I'm not a huge fan of some private companies but if they left the industry then we'd be wholly at the mercy of Chris Grayling, the DfT and the untamed Network Rail, so be careful what you wish for!).
Same with electrification, I guess - I saw it once as a good thing in its own right, now I've adapted to seeing it as one tool in the box (sometimes it's the best tool but sometimes it's a complicated/ expensive/ time consuming way to improve things).
I want to live in a country where we have a plurality of views and listen to experts (rather than an echo chamber), I want to live in a country where changing your mind is a positive thing and people are happy to admit that they have learnt new lessons (rather than the Corbyn world where our beliefs are formed as teenagers and we never evolve).
To take your own circumstances into account (living in Cornwall IIRC?), I'm happy to come on here and listen to the opinions of people living in Cornwall about how we improve public transport in Cornwall. Too many people only experience it in terms of getting the train from Paddington at the start of the school holidays, the peak tourist season, they have an idea of Cornwall that involves long distance trains requiring lots of luggage space. But for people living there fifty two weeks a year, the picture will be different, the through trains to Manchester/ Newcastle/ Edinburgh may be less important than something "ordinary" like finding sufficient 150s to provide a half hourly service into Devon. I'm here to learn, and that means listening to people who use railway lines regularly (over people who use them once a year at the busiest time of year and therefore have a skewed view).