Toxic positivity is a product of feminism or more specifically women.
I hate to say it but (alot of, not all) women are more worried about their "feelings" and "emotions" to handle genuine criticism, constructive or otherwise. So they create "safe spaces", echo chambers and bubbles to protect them and their feelings from outside criticism and differing opinions.
It wouldn't be so bad if they left this thinking to their personal lives, but no...they brought it into their professional lives where millions of dollars and thousands of livelihoods are on the line.