Making a weak legal argument that is bound to highlight the heartlessness of a corporation that tries to be famously accommodating and friendly to guests is a move that should have been caught before the argument was filed.
How much in goodwill and PR work did it cost them to make an argument that would have saved them maybe a million dollars in the unlikely event it worked.
There’s a reason that corporations will often settle cases that they are legally in the right for, and cost benefit analyses are a huge part of that.
"Disney+'s terms of services categorically shields us from all legal liability" is not a good-faith argument, and, if accepted generally, would create a world no one seriously wants to live in, including those lawyers.
This is especially true when Disney had an actually reasonable, good-faith argument in this case, that the law can't pass on liability for everything a restaurant does wrong, just because you recommend it, especially when the regulation and management of that restaurant is totally out of your control. This would create a horrible world where no one can make a recommendation without thereby becoming responsible for everything that goes wrong at that establishment later.