One of the biggest things labels look for when signing new artists and when working with their current roster is the commercial viability of their music. Will it sell? Will it be popular? However, artists want to maintain their artistic input and values when they create their music.
These two objectives can sometimes conflict. What an artist deems as their art that should not be messed with may sometimes not be commercially viable. On the flip side, creating a song that is more commercially viable may not fit with the artist's artistic vision. Sometimes, however these two attributes are in perfect harmony.
Check out this satirical take on the Anatomy of (popular) Songs by genre:
So what does this mean for you and your music?
When creating music, which of these results is more important to focus on? Commercial viability or artistic authenticity? The answer really depends on the artists goals. Some artists want to be mega stars while others just want to do their thing no matter who listens. However, in order to maximize your success or ability to at least support yourself as a musician, the answer is to focus on, well...both.
Being successful with your music is really dependent on your market size and market share. You don't need to create a Top 40 mass market hit in order to have a signifcant fan base. What matters is that you have a large enough fan base to support you and sustain you.
Maintain your artistic identity and be authentic, but listen to what your audience tells you about your music. They will let you know if your music is appealing or down right terrible. Don't be stubborn when it comes to this. If you create music and no one likes it, it's a clear sign that you need to do something to make your music more commercially viable.
Commercial viability doesn't need to undermine your artistic influence either. Even "counter cultures" and "non comformists" are a type of conformity. They have a conformity to their culture of being non conformists. That is a demographic subset that still has a commercial vability factor within it.
What matters most is that you are able to garner a large enough fan base that identifies with your music while staying true to who you are as a musician.