>If the ideal can change, doesn't that make classifying mental illness completely subjective?
Yes, it is completely subjective:
"psychiatric diagnosis still relies exclusively on fallible subjective judgments rather than objective biological tests" -Allen Frances, Chairman of DSM-IV
Who gets to define what the "ideal human" is?
If the ideal can change, doesn't that make classifying mental illness completely subjective?
If so, doesn't that mean you can essentially declassify your own mental illness if you can normalize it via political and social vectors?