Tantrums

Well, I've been thinking... this is one area where absolutely all books, resources and advice go in the one direction (apart from unconditional parenting and the continuum concept) and that is: if a child is having a tantrum you must never never ever give in and let the child have what he/she wants, civilisation will come to an end and it will be your fault for being a wimp. Even books like What every parent needs to know which build on a very positive premise of not leaving your babies to cry as it damages their brain then revert to traditional methods when it comes to toddlers and tantrums.
But I'm thinking that the sweet/tv programme/5 more minutes at the park might not be what's really important, I don't distinguish between different types of tantrum (the distressed and manipulating ones) as I don't believe my child is an evil creature put on this earth to misbehave and manipulate me. I think my child is the loveliest person with the best of intentions and that he is in some way distressed or frustrated and needs my help.
An example: the other morning Mr Toddler was woken up early as he had to go out with his dad, he does not sleep very well and is always a bit grumpy in the morning. When it came to get him in the car he started screaming "I want cake" (meaning a mini swiss roll) after having refused breakfast earlier. So if I had followed the conventional or supernanny method I should not have given in because he was screaming at me and not asking politely? Or just produced his toast from earlier and say if you're hungry eat this?
But from the look on his little face I could see that what he was really saying was: mum I feel weird and uncomfortable, I needed more sleep and that is why I wasn't hungry at breakfast, I've been put in the car and don't know why, I'm getting very upset and hungry now, please help me. Not having the language to express this (and would most adults?) he just cried and screamed for cake. Of course I gave him the swiss roll as well as cuddles and kisses (gosh, real bad mum...) and did civilisation come to an end? No, he calmed down and smiled, did he do it again the next morning as I had been such a pushover? No, he had his breakfast as usual and has not asked for cake since!