> It's not their creation, it's their idea.

Except in the cases where they literally create it? Every single idea and business started with a small group of people and often just a single person. Sometimes they create it, sometimes they pay someone else to create it.

If they pay someone to create it, do you think that person should take ownership in the company? Ok, maybe they should, but of course if they are taking part ownership they have to accept less cash right? Turns out most people don't want to deal with that risk and don't want to be paid in equity.