As they currently exist, I think they are bad for bitcoin and only exist because of regulatory arbitrage and fiat chasing gains.
In a more stable bitcoinized world there wouldn't be bitcoin treasury companies as they currently exist. Instead, we will have bitcoin banks that fill some of the roles of traditional banks
It’s a positive feedback loop. In general this is a good thing as long as it is sustainable, economically sound and accretive. Confidence is high, and the game was always about arbitrage on rules for different pools of capital.
As prime capital concentrates into Bitcoin, it will seem inevitable.
I'd like to see more companies and individuals buying that are specialized in industries besides "being right about Bitcoin" but so far no one else wants to buy ;_;