[RCMcKenzie]

I remember in the 1980's, people began using the word "bad" to mean "good."

I guess that's what's going on here. From Meriam-Webster's online thesaurus...
"off", adjective, over 400 synonyms, i.e.- "wrong, unacceptable, poor, lame, bad, deficient, terrible, horrible, awful, pathetic, wack, crummy, inferior, worthless, common, bush-league, trashy, cheesy, second-rate." etc. etc. Their words, not mine.

These are bad...