They have, and they realize that giving into him means he will do this again.
Not really, you can just pass a bill to prevent more shutdowns from happening?
And even if you don’t give Trump what he wants now do you really think that’s going to stop him from trying again? He has no reason to stop trying.
Do you truly believe that that they are not capable of performing a cost benefit analysis? Perhaps it's you who are not capable of seeing the true costs at play here?