It feels like a buzzword to me in this context and I don't think this exact term has to be used to be useful. I'd agree that it would be helpful to talk about the distinctive goal of trustlessness/letting people who don't trust each other reach consensus/not having to rely on a central arbiter/reaching consensus under conditions of not knowing who the other participants are/etc.
I think ii is imperative to note that adversarial environments are what blockchains are useful for. They're not particularly efficient as a means of storing data, so if you can trust and/or rely on suing your counterparties, you don't want to conduct your business on a blockchain. Yet the blockchain hype seems to be much about banks setting up their own chains etc, which is complete nonsense as that would be little different from a regular database.