If you buy a live lobster, how are you going to practically kill it before boiling it? Try to penetrate the hard shell to impale the brain using a layperson's skills and equipment and risk slicing off a digit?
Maybe another good reason to...not eat them as much.
I'm from Maryland where watermen in the Chesapeake watershed have been crabbing for generations. The cost of fishing licences and proactive regulatory restrictions have also contributed to the sustainability of the fishery here.
As Marylander's most of us have grown up eating crabs from a young age.
When you prepare crabs you must cook them fresh, because dead crustacea release a chemical which immediately turns the meat. It also the easiest and most effective way to know you are eating safe crabs and not diseased or unhealthy crabs.
Please stop projecting your morals on to us. Militant vegetarianism is no different than religious fundamentalism. Your are projecting your morals onto the rest of us. Please stop.