Take a look at who really benefits from this policy. Presumably, passengers are safer, but since it seems to be extremely difficult to implement an airline attack using liquid explosives (see TSA blog point #4), we are probably wasting resources by focusing on this threat. However, airport vendors and airlines directly benefit by preventing you from bringing your own snacks and drinks and then charging you $6 for a bottle of water. There is a post on the TSA blog about a woman whose egg salad sandwich was confiscated because it was deemed a "consumable liquid". And at many airports I can't even find a water fountain anymore.

Also note that any politician who would support weakening security measures faces the small but very considerable political risk of being blamed for an attack after restrictions might be loosened - on top of whatever "weak-on-terror" mud-slinging the politician would have to face anyway. Since the measures have strong airline support and it's difficult to find someone principled enough to take the passenger's side, we all face a painful travel experience.

I'm equally resentful about the ID-checking requirement since all the 9/11 hijackers had valid ID and it still wouldn't be hard to get a fake ID past the TSA. That requirement has a similar history of having nothing to do with security and a lot with not being able to sell your ticket to someone else and reducing the pricing power of airlines.