I think you are being unreasonable, but that is just my opinion.
Self-serve cash desks are a boon, as there is never a queue, and they always seem to have the correct prices coded in - which although the cash-desks with assistants are using the same bar codes for some reason is not the case there.
I would genuinely prefer shop assistants to be on the shop floor able to assist one to find things, as it seems to have become fashionable to stick stuff anywhere instead of having a logical progression of wares on shelves.
For instance, why should salt be as far away as possible from sugar, corn-flour, flour, vinegar etc?
And as supermarkets have floor to 6ft high shelves, I appreciate there being some 5' 9" assistant at hand to lift things down from the top shelves, as I am 5' 1" and the day is fast approaching where I will need help getting up again if I have to lift something off the bottom shelf!