Well, if we're going to be pedantic about it then it's important to understand that the quote itself is misunderstood: https://en.wikiquote.org/wiki/John_Steinbeck#Disputed

But regardless, I can't understand how anyone would understand that quote to meant that Americans feel like they are entitled to be Millionaires. Someone being embarrassed about not being something doesn't directly imply that they feel entitled to be that thing. More likely it means that they are working toward something they feel they ought to be able to achieve. Meaning they've always dreamt of themselves being millionaires but have yet to achieve it.