I can't help but feel the mistrust started primarily with the galleries themselves. I've always felt that you suspect in others what you yourself are guilty of. If you are a liar and a cheat, you believe everyone is a liar and a cheat. If you're deceitful, you expect everyone you deal with will be deceitful. It makes perfect common sense to me.
All an artist really wants is for a gallery to genuinely threat them fairly. I don't know of any artist who has said to me or mentioned that their only reason for seeking a gallery was to cheat THEM. An artist (at one time)needed a gallery. I know this is changing and the suspiciion from the galleries is that artistS are out to get them and cheat them of their "deserved rewards." Think about it. All an artists wants is to be treated well and get paid for the work they provide. Fairly. Where is it written that any galley should take a higher percentage of the sale if it didn't start with the galleries. I understand a gallery has overhead. But so does the artist. Actually I think the artist investment is greater than the galleries investment.
We both, the artist and the gallery share rent/mortgage, phone, utilities. the actual costs balance out in the end.
Only the emotional cost would be greater for the artist. Afterall, it's the artist and artwork on the line not the gallery.
If anyone is more trusting, it's the artist. Over time and in the current art market, artists share stories about galleries and have come to be suspicious. Why? Because galleries, by nature of the American business ethic ( an other issue worth discussing)is that they think somehow they are entitled to more or they have an inside track to the "money people" which entitles them to a greater share of the profits. I repeat, as I've done before, "without artwork to sell, there would be no galleries" Galleries are an invention of those who believed they could sell artwork which would give artist all the time in the world to paint. In theory, it's a perfect world. But the gallery owners saw an opportunity here to make more. They saw that artists are bad with business or were not interested in business or were too busy making art to conduct business. Enter the "greed" factor, which is built in to every business person.
From that point mistrust, suspicion flourished. Galleries started setting the rules, in their favor, and sowed the seeds for their eventual demise. Artist were also too willing to agree to "the gallery system". Long story short, we have the system we all love today. So when an artist has a website, it's only natural for a gallery to be suspicious and mistrustful of the artist. AND, in all fairness to the gallery, artists having been burned so many times, some are probably thinking of ways to cheat the gallery.
I'd be safe to say that all large companies in this county were built on mistrust and deceit. It's the American way.
When I was a child, my mother taught me to be true and honest and treat everyone fairly. When I was an adult and told her I declared some things I could have hidden on my tax return, she told me I should not have declared these things. I reminded her of her teaching and she, with a clear voice said, " that teaching was for when you were a child only". The world we're told is supposed to be as children, isn't what we eventually find out it is when we mature into adults. As most have found out.
Galleries could be fair and all benefit from the process, but I don't see that happening. Now that artists can and do have an alternative, they are exercising it more and more. I know I am. And only I am reaping the rewards. Does it take more time? Yes. Is it worth that time? Definitely.
In the end what galleries have to realize is there are more potential buyers surfing the net than are visiting galleries. Plus buyers know they can get a better price from the artist without paying for gallery overhead.

As a post script I'd like to add. Galleries exist today and will for sometime to come. Some are run honestly. Do your research when choosing a good gallery. Remember, it's your work. Take pride in it and don't ever sell it short.

I think that both the gallery and the artist should share collector information. Some potential buyers would prefer to buy directly from the artist in her studio with the easel and the paints, others would prefer to be shown paintings in the elegance of the gallery. I think that the gallery and the artist should share all potential buyer contact information with each other. If the buyer comes from the gallery's list but contacts the artist to see a painting which is in the artist's studio (not in the gallery), the gallery should get 50 percent of the commission (25 percent of the selling price)because the artist made the sale. If the customer sees a painting by the artist on the artist's web site which is not at the gallery and asks the artist to send it to the gallery so he can see it, the artist should get 50 percent of the commission or 25 percent of the selling price because the initial contact came from the artist, but the gallery made the sale. The details of this type of arrangement should be in writing in the formal agreement between the gallery and the artist. Both parties should actively be selling the art work. Naturally, the gallery should get 100 percent of the commission for a painting that is in the gallery and for which they make the sale and vice versa.