From what I have read I would say it started around 2017-2018. I was an early listener of the Keiser report and I think before 2017 the founder of Cardano has been invited as well to talk there so at least until around this time people were mixed. In my case I don't use the term shitcoin but... I never met Bitcoin people or Altcoin people in real life so didn't have the opportunity to discuss that anyway.