In terms of turning passions to profit, it is way harder to earn from a hobby that was self taught than to earn from other skills or jobs or as an employee under a boss.
I think those who are crazy enough to turn their hobbies into a source of income and attain wealth unimaginable in the end know how hard it is to be patient, consistent and persistent despite criticisms and many setbacks, to get to where they are today as successful. Whereas those who get employed and have to work to earn a salary or earn from a skill that was learned somehow, don't encounter this much difficulty that may lead to financial freedom and breakthrough.
What do you think?
Let me assume that you mean that becoming an entrepreneur is more difficult than working for an employer and getting paid. Every creator or business owner will have to work harder than an employee because he would also enjoy the benefit alone. Passion for your a self employed job is what keeps an entrepreneur going even when the business is not making profit. If you don't have passion for your business or the hobby you have monitised, you might give up if the business is not going well. A business owner will have to learn how to manage challenges because it will surely come.