Not everyone can be an entrepreneur because everyone's mentality is different, and also not everyone has easy access to funding that is needed to become an entrepreneur, so there will always be people who can only be employees and that does not mean they are slaves.
The tought that employees are slaves will damage your work ethic, so you cannot become a productive employee, there are also employees who can become successful people, even though their wealth is not the same as an entrepreneur but their assets are enough to live and can also be inherited by their descendants.
Such thoughts should never interfere with a person's working ethics unless the person is already prepared to leave the work. Like you already said, everyone is not made to be and entrepreneur and I have said it before now that some persons do not even have the goal to become their own boss in life, some persons just want to graduate from the university and get a good paying job to be able to get married, give birth and train their children. That's just the kind of lifestyle some persons want. Also, even if you want to start a business, you will need some funding which could make you get a job to be able to raise the funds you need.