Yeah, I agree with your examples aside from the ability to validate XML; I'm not a heavy user of json but I don't believe it's possible to tell whether a document is well formed. Anyway, the lack of rational means it doesn't address essential vs accidental complexity. Are the harmful items harmful because they have lots of accidental complexity? Or are the problems they exist as a solution for simply hard problems? If complexity of a harmful entry is mostly essential it would be interesting to know why it was still considered harmful. For instance, Bash is considered harmful but is nice as a user shell compared with say, sh.