I guess the concept of burning coins is to reduce supply in the hope demand stays the same thereby increasing price. This is shown to exist in the real world where real estate has limited supply resulting in many markets steady increases as incomes and demand increases with population growth.
But i see your argument is that by burning POB we will have less tokens distributed, and hence demand will fall too and the hoped for price increase might not happen. This is a very real possibility.
However I like to think of it differently, if i get half the tokens for a post or creation, I dont really care if the token is double the value. So it all comes down to if burning will result in a more narrow distribution of rewards or not, that depends on curation behaviour so its really hard to tell what the true outcome will be.. hopefully thats some food for throught when thinking through the complex behaviour impacts that burning may have.
Demand in an overall sense that the platform itself is quintessentially demonstrating the Proof Of Brain mechanism and if there is a less range of evidence to provide Proof Of Brain, then there will be knock-on effects which we currently cannot see.
This is exactly what I've tried to raise, food for thought so others can settle on their own decisions.