There are some really bizarre and spiteful comments on this thread as well as loads of stuff that's either a massive stretch or plain manufactured.
Whatever you think of an institutional monarchy or the individuals involved in this one, they're all human with emotions and the fear of stuffing up on the world stage as this was televised live and recorded for history.
Everyone would have been a bag of nerves, concerned that no one stumbled, dropped anything, got the words mixed up, or that the crowns might slip or tumble off. The stress of all that must have been utterly overwhelming, no matter how many times they rehearsed, not to mention security concerns for everyone taking part.
For Charles it would also have been mixed emotions, memories of his mother and grandparents and that they are the only people who would have known what it's like to go through this process, and the realisation of how enormous an event it was.
As for kissing, hugging and warmth. It can't have been the easiest thing to stoop and kiss the cheek of someone sitting balancing a crown on their head. You can find plenty of photos of the royals kissing in greeting. Try Charles and Zara for some good, public examples.
This was the event that formalised the change over from 70 years of someone else being centre stage. The first occasion where Charles was the figurehead, and the day must've been a terrific strain. I imagine they all found it tiring, overwhelming and ultimately were massively relieved that it all went off ok, not only for the family, but for everyone involved in organising and working to make it all come together. I just can't fathom why people want to nit pick over that.