Yea, and Transformers 2 made over a billion dollars and is one of the worst films ever made. (Not that ST is that, but my point stands)I will say even if Stranger Things was at the bottom of the GSAT scores what sold the most tickets, merchandise, and hotel rooms.. Stranger Things 100%.
No one is saying 0 IP's though...I don't think we'll be seeing any decrease in IPs any time soon, even if so many are off the table due to ownership challenges. Look at the park itself, off memory (ie, probably wrong) Rip Rocket is the only ride I can think of that isn't based off a TV or Movie IP, but it could be argued it's a music IP-based ride.
I think people that go to the park specifically expect movie based rides and attractions. I, like most super fans who go every year, really enjoy the originals but let's be honest, we're going no matter what. In order to keep attracting new guests, they need to give them something they want to see. "Scarecrows in a field" or "Mountain Yeti" sound awesome to us knowing full well what Universal is capable of and what they have done in the past, but to Joe Consumer that sounds boring and generic. Sounds like something their local hay ride down the road at home has. "The corn maze down the road has scary scare crows and only costs $35."
But something that has the hottest horror property of the time (Walking Dead, American Horror Story, Stranger Things, etc) or all time classics (The Shining, Exorcist, American Werewolf in London, etc) is worth packing your bags and making a visit to Orlando to attend.