The 737 has a manual method of ensuring the bleed system is connected to the pressurisation system and as such it will always be a weakness. It has also been recommended to Boeing that they include a visual warning of high cabin altitude and not rely on an aural warning which is the same as the take-off config warning.
Unfortunately the 737 is still reliant on operating philosophies that assume a certain level of experience and training which is no longer a valid assumption. To highlight the change in operating philosophy, look at the B777 QRH which has been designed to reduce as far as possible, crew actions.
Alexban- The incident I think you are referring to involved two elements that led to the masks dropping. The incorrect numbering of the cracked windscreen was the first element; not understanding that setting the cabin altitude to 13000' would lead to the cabin altitude warning horn, was the second.