Yes I'd say that you're wrong with that.
To start, it wasn't that short sellers were ruining the market. If you spent any time there, you'd see that they, too, short stocks.
Second, it definitely wasn't made up. GME was tremendously shorted. And there were more shares shorted than existed. This is not a unique phenomenon and is possible due to a concept called "naked shorting".
It also didn't stop going up because people pumping it stopped. They literally disabled the ability for people to buy more. That is what killed the momentum. https://www.cnbc.com/2021/01/28/robinhood-interactive-broker...