the CSAM part of the debate is about which players in this game have an incentive to degrade the reputation of bitcoin. those are obviously competitors to bitcoin, and the number one competitor to bitcoin is the JPM/Consensys backed Ethereum project.
it is true that the content requires special tools to decode, but all binary data requires special tools to decode, even text requires a mapping between ascii/unicode and the glyphs to render text to a screen, but this doesn't change the fact that such data is displacing legitimate transaction content of private individuals making payments and managing their L2 systems, so filtering helps lower the clearance time of legitimate transaction content. transactions themselves also need "special software" to decode, so this whole line of reasoning is a dead end, and does not clear the spammers of their indictments.
and it's a very good reason to oppose anyone promoting non-monetary transactions on bitcoin, because they are going to use it to scam and defraud users with their fraudulent proof of stake and mutable governance of protocols that is the base nature of all shitcoin chains, trying to dress scams in the legitimacy of registered financial operations that are themselves also, in fact, fraudulent and malicious to most people stupid enough to participate in these "markets" of manipulated, endlessly debased tokens (stocks, bonds, smart contracts, all the same if you ask me).