Spaceflight

cold welded

Oh yeah, I forgot that was a thing. I agree, if literally the entire station is cold-welded together, that might make it too difficult. But if it's "just" Zarya and Unity that have the cold-welding problem, why not at least disconnect and reuse some of the modules on the other side of Unity, or at least some solar panels and stuff?

If you think about it, even just attempting to salvage part of the station could be an interesting and useful experiment in and of itself, regardless of whether they expect for it to be successful.

at that point, why take on the baggage of the rest of it.

Because being attached to the legacy ISS, at least in the short term, would preserve a lot more space for activities than launching a single module standalone and letting the rest burn up? I mean, sure, if we already had a half-built replacement station in orbit right now, I'd say let the ISS go. But we don't. Right now it's very questionable whether we'd have anything flying by the time it's scheduled for de-orbit, and I find both that and the notion of replacing the relatively-gigantic ISS with something Skylab-sized (at least for a few years) to be an unacceptable downgrade.