For example, I joined in August 2017 and stopped using the platform till February 2018. Why? Because, bloody-hell, no one cared. And my posts were good quality ones and yet no readership.
Yeah, if they want "high quality original content" then they need to make sure new members get some encouragement.
Participating in contests is great advice. I've also found that (quite surprisingly) some of the larger accounts actually get very few comments, and so, writing some critiques of the "top trending" posts can sometimes work to your advantage.