No, they weren't. It was considered a childish hobby by most people and most of the games were kid games during nintend's reign. Playstation consoles broke sales records that nintendo and the rest dreamt of but couldn't do the vast majority of the time. Playstation home consoles pushed the gaming market into what it is. Third party devs were able to sell record breaking boat loads of games thanks to the success of playstation consoles.
teens/adults becoming gamers was just natural progression, kids in the 80s became teens/young adults in the 90s so developers/publishers naturally made games to cater to their maturing customer base.
games aimed at an older audience were becoming more and more common in the early 90s and would have continued to increase in quantity with or without Playstation.
When the herd loses its way, the shepard must kill the bull that leads them astray.