Thanks all for your input, it is much appreciated and eye-opening. Just to clarify, my post is only marginally related to the thread. The driver is obviously right in this context, and the Platform Staff performed poorly. Were they safety-critical, money is on that they wouldn't even start the dispatch process. I'm not sure why these staff care about the timetable or delays more than safety.
In hindsight, the rare scenarios I describe may have just been a driver with the hump. Not fair to lump all other drivers in with that, as easy as it is to do. Most encounters are positive. To clarify one situation, by "doing my job", we are required to make sure that the driver "is ready" before asking the signaller for a signal. The fellow was taking a bit to set up, so naturally, I started to get concerned. In this situation, I was the unfortunate victim who dared to walk up and ask "all good driver?" before being subject to some very strong words followed by a threat to not take the service. That day I learned you *can* set-up 20 seconds before departure!
As for cab conditioning, it was something I was interested in an answer to. It's not related at all to this post. I didn't consider that the AC may be stuck in heating/cooling, which I can understand. I definitely have a better outlook on why air-con faults can take a train out of service. I must admit that prior my attitude was that drivers would not find the temperature to their liking, and refuse to take the service.
Once again, thanks for the constructive opinions and perspectives from all. I do recognise the animosity in my post, and apologise for that.