I would have to agree with you that a host/hostess shouldnt have an attitude, but there are a few things to consider in your scenario. First, there were probably reservations for those tables coming in and knowing that two people cant eat in 5, 10, 15 or even 45 mins she declined to seat you at an "open" table. Second, the table may have remained empty even after you left because of jerks that no-show, and theres nothing she can do about it. Given that you already made yourself comfortable at the bar, she wasnt really under any obligation to seat you, especially if you made it clear that you were eating/drinking at the bar.