re: How misguided were kids when they chose grunge over hair metal?

There’s a real good oral history of hair metal - “Nothin’ But a Good Time” - that talks about how the genre killed itself with too many bad bands. Things started to dip around 1990 - that’s when ticket and record sales dipped for some of the second tier bands like Cinderella and Ratt.
Hair metal and grunge had a lot of the same influences - Kiss, Aerosmith, Alice Cooper. It’s just that the grunge bands threw a little more punk in the mix.