Yes, it is important to try and teach your kids that compromising is part of life, that you can't always get what you want, and that you should try to secure financial security before 'shooting for the stars'. But parents alone don't do everything. I feel our whole society is strangely wired to tell people to follow their dreams, not to listen to naysayers, etc. Try telling kids that they'll have to do mindnumbing
tiring shit 5 days a week to be able to afford 2 days of rest where they can be 'someone they want to be' is a losing proposition.
I'd feel better as a parent if they liked a lot of stuff (manual, intellectual, artistic, helping, electronics, clothes, cooking, selling, building, repairing, teaching), had an open mind and excellent work ethic, so that when they find themselves doing any job, they'll try to excel, find something in it, and 'be who they want to be' in their job too. Office politics, the way you treat others, helping colleagues, improving your skills, taking responsibilities, being a responsible and helpful member of a team or a society, keeping ethics standards high... You name it. They can also be achieved through work, while not really being fond of what you're doing. CPA, blue collar jobs (or plumber for you) don't seem to be dream careers, but there's many opportunities to be a productive, impactful, helpful and happy member of society while working those.