I think criticism of MicroStrategy's strategy should be allowed, without "vilifying" Saylor or describing his business model as a Ponzi or similar. For me it's a currently viable, but risky strategy. And I can imagine a lot of the criticism is rooted in these risks, be it due to fear that Bitcoin could be negatively affected, or simply to warn to be too bullish on his stocks.
First, it's true that we don't know Saylor's real intentions. There is no guarantee that his business model works for longer terms. We only know that he was able to sustain the model in a macro bullish Bitcoin uptrend with an intermediate 76% crash but a relatively fast recovery in 2023, where MicroStrategy didn't run out of money even if there were some rumours. But what if 2022 the price had dipped deeper? What if a very deep dip happens in 2026 because of whatever uncertainty that makes Bitcoin hodlers panic? And what if he simply sells eventually, e.g. when several Central Banks already have acquired some BTC, because he thinks that "the time is right to get out", e.g. because he thinks Bitcoin is close to an adoption/price ceiling? I think this all are scenarios which are possible.
Second, his buys are not really helping Bitcoin to stabilize. He
tends to buy when the price is already high, so the cost is higher than a typical longer moving average or a DCA. This is also a bit logical, because he will be able to raise more funds when the market is bullish. But this way he amplifies bubbles without helping much to establish a bottom in bearish phases. And it makes his strategy also a whole bit riskier because there's a real chance that
BTC falls for a longer time below the average cost which is currently already at 56000 according to BitcoinTreasuries.
I think it is not FUD nor vilifying to point out to these risks. In any case, I don't think that Bitcoin will be seriously harmed if MSTR fails. But it could lose some investor confidence, and a MSTR fail would for sure be very bearish for some time.