Schema changes are pretty much the riskiest damn thing you can do with a database, so it's natural people would be extremely interested in being able to confine

Schema changes are pretty much the riskiest damn thing you can do with a database, so it's natural people would be extremely interested in being able to confine as much of that as possible to transactions, even if changes are rare (which, arguably, they're rare in no small part because they're so risky).