This is, like you say, a case of group psychology, but based on economic arguments.
That may be a prevailing view but there's no empirical evidence in support of it, so I'm skeptical and treat it as conjecture.
The thing is that in the Bitcoin community the belief is so widespread that everyone who wanted to change the paradigm "Bitcoin's economic value depends on it's supply that is limited to 21 million coins", would have have a hard time. The paradigm may not have an exact proof but the economic theories to which most "Bitcoiners" adhere support it. This is why I consider it almost impossible for that aspect to be changed - not 100% impossible, but 99%+ ...
I find it hard to replace "cryptocurrency" if we must explain something that complicated like "proof of burn".
That's where my marketing and social psychology background gives me a different view, allowing me to respond - What, like they have to explain the changes in suspension, steering and engine management parameters that lie behind pressing the Sport button that you see on many modern cars? Who says we must explain proof of burn to people who don't want to know?
Obviously one could market Slimcoin as a simple form of "Internet money", like some try to do with Bitcoin, or as a simple tool for Web2Web publishing. In some cases that would be the way to go, for sure. The problem emerges if we want to describe Slimcoin's advantages versus other competitors. Here, I think, at least a very basic Proof of Burn description would have to be included. And I think there are advantages (as I wrote
here), above all the stability-favouring aspect.