In a way, yes. It is failing in encouraging children to think outside the box. Kids aren't scared to try new things naturally, we just make them that way because we teach them that mistakes are "wrong". I know my kids are like that already. Maya is afraid of being wrong to the point that she doesn't want to always try new things because she can't do it right from the get go. I know that it is partly my fault though, but I'm actively trying to break that habit in her.
I think that he might say that those other systems you mention still do a disservice in the education of arts and creativity (ie. making mistakes is OK), though not as bad as a traditional system. Homeschooling maybe the least because it really is based in alternative education, so much so that it completely removes the child from a traditional setting.