The whole "artists don't care what others think" thing is a giant lie. Most artists care what others think of their work more than anyone else in the world. Creativity is an unsure and scary thing, and a little validation makes us feel good. It's poisonous.
The world can be a really crappy place. People love to pick apart artists (who knows why), and many talented creators internalize that chatter and either fall in line with the status quo or quit altogether. It's a stupid, unnecessary tragedy.
What's strange is that the ferocity is at its most intense within the art world itself. Artists conciously eschew constructive criticism for willful decimation of the creator for the sake of cheap personal satisfaction. The Internet makes such behavior all the easier to spew. I'm not saying there isn't bad art. But people confuse "I don't like it" or more often (though they'll never admit it) "I don't understand it" with "it's bad art." Good art is innovative. It shows a control of the medium and its techniques (and a controlled disregard for them, if desired, à la Pollack). It conveys an idea or emotion effectively and with clarity. It often (though not always) wears its heart on its sleeve, being an extension of its creator. But here's a secret: most people are awful at talking about what makes good art. They confuse critique with criticism borne of insecurity or smugness. They confuse thoughtful discourse with denigration for the sake of appearing academic or enlightened.
I went to music school for composition. I write the unpopular unpopular music. Even most classical music devotees would rather hear 200-year-old repertoire than that "modern" stuff I write, whatever that descriptor means. My most popular piece is horrendously unpopular. I don't care. Why? It's who I am. The few people who do appreciate the sort of music I write like what I do. More importantly, I've ached and agonized over every note and done everything I can to make that music the best I could, but once I put it out there in the world, it's out of my control. And we should never gain satisfaction or be proud or disappointed in ourselves based on things out of our control. We can feel lucky to be appreciated, but pride should be something we assign ourselves out of an internal validation of our efforts.
You must divorce financial success and accolades from your peers from success as an artist and self-actualization. You see, all you can do is be as introspective as possible, be as informed and knowledgeable of the techniques, history, and repertoire of your craft as one can, and create your work to the best of your abilities without reservation. Once you've done that, what happens to it when you put it out into the world is beyond your control.
And of course, the fact that it's beyond our control coupled with the very human desire for validation means a lot of us engage in behavior ranging from hanging our self-worth on the critique of others to simply pandering in our work. Pandering might work if you know your audience well, and if you're in this purely for financial gain, well, all the more power to you. But if any shred of you is in this for self-expression, you will never be truly satisfied when you're being disingenuous.
Here's where it gets really tough, though: I'm not saying to completely tune out the outside world, because there's useful feedback there. Don't confuse constructive criticism of your technique with disapproval of your creative vision or even more importantly, the expression of your inner self. No one gets to tell you the right way to do that. There is no absolute. Anyone who says there is is saying so because they have a need to legitimize themselves in some manner to assuage their own insecurities. What people can tell you is how much clarity you possess when you translate inner musings to outer expression. If they're really savvy, they can tell you how you might be a better introspector. But if their critique consists of smug dismissal, the critique was never meant to help you so much as to lift them up by cutting you down. It's a sickening rite of passage in most artistic circles to put one's work before their peers so it can be torn to shreds, only to see if the creator can come out on the other end with the will to carry on. I see it a lot in younger undergraduate students: they think they have to tear something down to legitimize their opinion, to feel as if they are part of the inner circle. But that preconceived notion of how to critique creates a biased viewing, and biased viewing are rarely worth much. Unfortunately, I see that behavior continue beyond those early undergraduate years as well. I've always said that unsubstantiated opinions are a worthless currency most often wielded by the unexperienced, the uninformed, or the overly jaded. The same goes with airy praise.
Want to be a better artist? Turn off your computer. Deactivate Instagram. Put two middle fingers up to the world and go create and don't share your work until you're so proud of what you did that the only reason you're sharing it is to gain more business so you can make some money off this weird thing we do or just for others to enjoy it, free of any need for validation. And of course, that's the other catch. Even if you pull it off: you master your craft, you suppress the need for external validation, and you tune out all the static of the wannabe critics who cover their own insecurities by tearing others down, you still might not have any success in the financial or popular sense. Rarely if ever is financial or popular success a measure of artistic merit, though. You might not be what the world is looking for at the moment. You might unfortunately not have the amount of talent needed to break through the veritable din of creative output. But if you truly believe in the art and you want to feel self-actualized as an artist, no measure of success will satisfy you if you've compromised that inner vision.
The adherence to who you are comes first. If the financial and popular success never comes, well, then you have to ask the tough questions like if a career somewhere else with art as a serious hobby is more appropriate. But first, find what makes you happy and who you are in the world of creativity, because we're awfully lucky to be in that world in the first place. Then, build the more practical parts of your life around that place.