It works that way for me too. I’m (among other things) a game developer, and a few years ago someone asked me how much it’ll cost to make a game for them after looking my name up from one of the games I’ve made.
I gave them a quote without thinking too much (“$100/h, maybe a bit less if it’s something really interesting”[0]) and they were shocked, saying something like “I didn’t think you made that much money from these games!”. Well, if I did I wouldn’t be taking on contract work to begin with but you’re not getting the same rate as my own projects :)
[0] these days it would be more like $150/h.
Interestingly this holds up even though I'm now coding up my own ideas - even though I'm calling the shots on what I work on, they're still constrained by what there's potentially a market for, and so it's still not really passion coding. If I were completely free of constraints, I'd do stuff that's more useless, more prestigious, more beautiful, with fewer corner cases and fewer dependencies on outside software. That's economically unviable (and kinda solipsistic, too), so I don't.