Something bothers me about that divide between writing as art and writing as a craft/profession.
As someone who's gone through the process of breaking into creative work, my experience tells me differently. You can't separate it like that.
If you want to be good, you have to work on developing it for the majority of your waking time. That will not work out as well if your full-time job is completely unrelated to the field in which you'd like to do "art." You will be wasting most of your productive time not advancing your basic skills, and will be too drained and tired to do that after.
So you have to sell out. Some examples:
I wanted to be a painter and do cool graphics work. Instead of goofing off on it as a hobby in my spare time, I got into 3D graphics, found out what pays and built up freelance work. Does it mean I'm not doing art if I'm working on arch viz #349857345? I'm still building aesthetic skills and other abilities while doing that "boring" assignment. This will help when I go on to make something creative.
I wanted to be a musician. So I'm playing gigs at clubs, doing covers of songs I might not have touched otherwise because I have taste. Yet it all advances my musical skills and abilities, so playing those few songs that I hate means I'll eventually be much better when I play the ones I love, or when I work on my own stuff.
You need to work on your craft/profession if you want to do it as an art/vocation, is what I'm saying. You can't separate it, it's like building a house without the foundation. Gotta do the sellout gruntwork without grumbling.
It ties into procrastination because it is all about delayed gratification. We don't want to start working because the payoff is so far away on the finish line. So I don't want to practice playing Jolene, but if I keep that long-term goal in my head, that makes it easier.