Is that because when you turn a hobby into a business there are lots of non-hobby tasks and requirements? Like sales, marketing, etc, etc?
Or because of the pressure of delivering the result?
Or for some other reason?
Worst case, if you get burned out on the new job you will not only no longer have a job but also won't enjoy your hobby anymore.
basically, yes, all of these reasons apply.
I'm good at drawing, not at selling myself; my work sells itself to a certain degree but that only gets you so far. Not everything I'm paid to draw is a thing I love to draw, either. And sometimes even a thing I love to draw becomes less fun when it has to meet someone else's approval; going back and forth with a client is a very different feeling than "I start drawing and I fix things I don't like until I'm happy with the piece".
Deadlines suck and I mostly arrange my work so as not to have any. Yes, this is a luxury. It probably means less money but I make enough to get by.
It's mainly this. It's not a hobby when the customer needs their product delivered by Thursday, not is it a hobby where you need to maintain a certain output to pay the bills.
Sales and marketing are just a thing that you get used to.
I regularly wonder how to balance the intrinsic pleasure with extrinsic value. I keep thinking that people could meet on the point where both find great pleasure in this venture. Something rare in the current economy it seems.
So I think for this to work, you have to go full collectivist: gather up a bunch of people interested in different things, produce stuff for each other and divide equally with no money being involved in the transaction.
Never take orders.
But yes, some artists have famously gone through intermediaries such that there isn’t a feedback loop possible.
I also successfuly monetized my hobbies.
All three times it has become lucrative, but none of them are hobbies any more.
One of the important things along the way I've learned is that what makes hobbies relaxing and fun isn't about the specific task you're doing but the fact that it's about enjoying the process of making/doing rather than feeling pressure to deliver the end result.
That's not to say I have any regrets about what I did - it's turned into a pair of businesses that are interesting and challenging in their own way while bringing in some serious coin - but the whole adage about "do what you love and you'll never work another day in your life" doesn't apply to running a small business.