Similar to Ndebele "nsuku zonke", which also happens to literally mean "days all" , or put more appropriately "all days".
I'm also curious about this. I would think that siku_zote would be more typical.
if you read DiegoJaviUnlam's comment, you will see that sikuzote is a word in its own right, meaning always.
If you write it with a space like that, I would understand it more literally as "every day", while sikuzote means "always".
Big difference in this case, as I understand the phrase as a complaint that the person is eating all the time (not just every day)