I would love to see your precise taxonomy of crappiness.
What is the unit of measure? Crap per millimetre?
That's the problem. There is no objective standard for what is OK and what is crap. For example, I think Lee Friedlander's street work is barely better than a 12 year old with an Instamatic on family holidays in the 1970s. But a
whole lot of people disagree strongly with me on that. Who's right? Do we vote? (Keeping in mind that some of the most dreadful artistic sewage of the past hundred years got "voted" on by people with their purchases. Thinking of things like ... oh, nevermind.)
(There are certainly standards for what makes art great or not, we just won't live long enough to know what - if any - of our own work meets that standard.)