Sure, there's a lot of noise in using brainteasers as a predictor of problem-solving ability; but IMO they do offer some predictive value. It's an opportunity for them to see how you think. They're hiring you to solve problems - and the easiest way for them to gauge problem solving ability is to ask you to solve problems.

"Would you want to work with the guy who builds a water-displacement scale/barge, taxis a 747 to the docks, and then weights the jumbo jet using that, instead of simply calling Boeing in the first place?"

Umm, just because you CAN solve these brainteasers doesn't mean you don't know how to call Boeing! Knowing more than one way to solve a problem is almost never a weakness.

And as for the blind bike example, the candidate was not being practical, just being a pain in the &*%. Just answer the question without being a smart alec.