Not entirely true. Rothko did it just as right as Georges Braque and Manet and Rembrant. They were all very different.
However, there's a definite line between things that are good and bad in art. It's not all subjective. I thought it was when I started school, and very quickly began to understand otherwise. Yes, some things are a matter of taste, but there is a good and a bad.
Also - those who are saying people are worrying too much about the internet - This is a resource, and people like having that resource. People can come here, get crit, learn about new stuff, get new ideas, and learn different perspectives... if people didn't share information life would be a lot lamer, having everyone figure shit out for themselves. The people that are worried are the people that see MA going downhill and don't want to see that happen, because they want to use is as a resource.
Yea, some people spend too much time here and not enough time shooting or doing things, but that's not everyone. I ski 100+ days a year(/claim) and still enjoy coming back here and reading about new gear, giving crit, reading opinions. So, to me, it does matter, because it's been a good resource in the past and I've learned a lot here.
And I agree with what Jeff_Lo said.