Contrary to what your favorite local rapper has to say, selling out is the point. We create art to share it, or sell it rather. And unfortunately, if an artist were to give away all of his or her creations for free, not only would he or she not be able to create art very long due to depleted resources, but he or she might actually die of starvation... Seriously. That is how life works -- especially in the fiercely competitive landscape of capitalistic America. Furthermore, the stylistic evolution of an artist overtime is inevitable. The same propensity for creative experimentation that causes an artist to "change" their style or "compromise their creative principles," is the same creative energy that allows them to be an artist in the first place. You can't have one without the other.
Creating art ultimately cost a lot money and is a huge risk to take on -- one of the biggest in commerce -- and without a financial reward, the outcome is literally destitution -- hence the term "starving artist." If you spend more money than you make, your life is unsustainable. So fundamentally, growth and wealth accumulation enable an artist to cover their costs and create more value for the consumer instead of limiting their production -- which is what we all want, right?
"Selling out" occurs when early adopters witness their obscure, secret obsession grow into a national pastime. They feel as if they were the early pioneers to a trend that is now ubiquitous. They no longer have a creative edge over their peers and feel unappreciated after having taken on the risk to support an untested "product." They are now 1 in a million. They feel insignificant. They feel abandoned. They feel betrayed. So they blame the artist.
If you believe that an artist, musician, or publication should reach a certain threshold of followers, allowing them to become financially independent, and then deliberately attempt to slow down growth to remain stagnant, you are mistaken about what it takes to create art or anything of value for that matter. If you are not growing, you are shrinking, there is no staying the same.
Even before capitalism, the market forces were naturally in effect. If you wanted something from your neighbor, you would have to offer that person something of equal or greater value -- whether it's a tangible product or a medium of exchange, like money. Otherwise, you were out of luck. And if you are an early settler of America, obtaining that good or product could mean the difference between life and death. Therefore, one MUST produce enough value equal to that of which they wish to consume, and moreover trade that value wisely to parlay the profit into greater value production.
An artist is the truest form of an entrepreneur, and in business, the objective is to create value that meets demand. If you don't meet demand, or meet demand as minimally required, then temporary stagnation will transition into terminal decomposition. Again, nothing ever stays the same -- you are either moving forward or backwards; growing or deteriorating. It's your choice in what direction you move and how you judge others for their success. If you want your favorite artist to stay in business, growth is inevitable. Change is inevitable. Just enjoy the ride and appreciate that someone is taking on the risk to create value for your benefit.