this is not what cake-eater means.
cake-eater is a term used to describe suburban (often white) spoiled and or rich kids as opposed to the poorer neighbooring suburbs or city kids.
From either "Let them eat cake" or everyone else just eats cake on their birthday, but these fucking cake-eaters eat it for breakfast. An example of someone like this is anyone who would use large sums of their parents money on redicuolos projects (like building a garden or adding an extra room to their house) that they never finish.
A cake-eater is a rich person who gets their job or assignment because of their family's status not personal drive or knowledge. Typically they do a piss poor job but never get fired or demoted because of their stature, even though more qualifed people could do better.