Depending whose viewpoint you are taking. Just think about this for a moment. Who's doing the criticizing?  Likely someone who works in a conventional job.  

If you work as an insurance broker, or a doctor, or windshield installer for the automotive industry, then you work regular hours, for an expected wage, with structures for safe practices and regulations around what you can and can't do. You also likely have industry standards for education.  If you fulfill x,y,z, training and earn your certificate then you can perform that job.

The structures and expectation when you have a regular job are easily understood and most people can work within them just fine. 

Artists on the other hand, often work irregular hours, and perform many things that are not directly measurable, and are easily judged by those who work differently. Plus there is no x,y,z program of training that guarantees anything for an artist.  You can go to university or some other post secondary training and still have the same challenges of marketing and creating a body of work that is marketable as those who did not go the university route. 

Then there are the things that artists do that don't correlate to an hourly wage structure. What about the hours and hours an artist spends conceptualizing new ideas, trying things out, practicing with new materials, pricing the materials they would like to use - only to realize the cost is too high, then spend a whole lot of extra time trying to find a new solution?  How does all this get factored in? 

Conventional jobs = doing a job + get paid for that job. 
Artists = try a bunch of things, spend a whole lot of non-billable hours to produce something, and hope it sells.  You get paid for the one item that someone gave you money for, not the hours and hours it took to produce that one item. 

In reality, business of any sort is very simple.  You make a product that someone wants to buy and then you assist that person in buying it. 

Simple.  
For artists, being that there is no inherent business structure, they have to decide, on every level how they are going to structure their business. I think this is where it gets a bit overwhelming.  

When are they the most effective at their work? Is it midnight to 4 am? 
Where are the people that want to purchase what they have produced?
Which shows/exhibits do they want to be a part of?
What are the commissions/costs to be a part of those shows?
How are you going to display your art so it can be seen in the best possible light?  Can you schlepp all that to the venue yourself or do you need someone to help? 

How do you price your work?  
Do you sell it framed or unframed? 
How do you talk about your art so the possible collector is intrigued enough to enquire about purchasing it? 

Then comes all the shipping and packaging questions. Oh and the website.  Which platform, how do I take payment, how do I keep an inventory of finished work?  Where did the blue abstract piece go, anyway? 

It's a lot.  From an outside observer artists may be judged because what they do does not fit into a neat, regular system.  

The freedom to decide how to be an artist, is part of the appeal and attraction.  The freedom to design, tweak, sell and promote their work however feels right, to whomever it feels right, is really a blessing.  

If you are an artist, don't worry about the criticism, you get to do you.  Make the decisions you need to make, get some help if you need it.  Keep records of your work.  Pay your taxes.

Another thing about being an artist that's super cool.  Anyone with the right training can sell insurance or install a windshield, or style that new haircut.
Artists create something from nothing,  Something wonderful and new that can only be created by them. There is no recipe.  The product comes from their unique inspiration and their skill with their medium.  The possibilities are endless and never the same twice.  

Yeah to all the artists out there cutting their own path through the amazing opportunities, doing it their own way.