You are going on a hypothesis though, rather than actual data. There are quite a few inflationary coins, like Doge which have had a massive market cap increase, even as their supply was increasing. (Compare doge market cap now with what it was in 2014, and then compare the number of coins in circulation between 2014 and 2018 - the increased supply made no difference).

Have you actually tried to quantify exactly how much steem was burned and when, to analyse the impact?

For example, you could do an analysis of the null account and compare it to the price at various points. I think you need to crunch the numbers first to prove your theory, rather than just rush ahead based on a guess.