There's an organization called fairvote.org that has been promoting it for years even though it doesn't work. I have heard two theories as to why they are still promoting it:
When they chose it, it seemed like a good idea at the time. Once they were committed to it, they couldn't back down without losing face.
They are Cloward-Piven anarcholeftists who are using it as a tool to screw up democracy.
I followed the news from Maine when they were approving this crap. The people who wrote editorials for and against it were equally uninformed. Those who were for it could not explain why it was any good and were only vaguely familiar with what it was. Those who were against it were suspicious, but lacked the technical knowledge to explain why.
My big example of why Ranked Choice voting is not the panacea its advocates claim is the Senatorial Ballot for Victoria’s 2016 Election