I agree with the question should be: Why NOT aspirate. It is so simple, easy and fast, and is just an extra step to double secure everything. In the 80's NASA became so cocky with the Shuttle program, flying shuttles was like talking the bus up and down. Then the Challenger tragedy due to human error. Then the Columbia tragedy due to Human negligence again. There is always room to improve. It is hard to think on what else can be improved, but if you know already, DO IT. You know aspirate can save you from a very bad experience. And even if you don;t experience bad sides, you will waste your juice going into a vein. Stick it in, pull the plunger, literally 2 seconds, then shoot.