Are drawbore pins unecessary in vertical joinery?
It's fairly common to use mortise and tenon joints to join the legs of a workbench to its feet and arms (top bearers). I see a number of people putting in drawbore pins to secure these vertical joints. Now don't get me wrong - a drawbore joint is incredibly strong, and doesn't need glue, and if you use the right accent wood for your pins it can look really good, but apart from aesthetics, would drawbore pins really add much to a vertical mortise and tenon joint in a woodworking bench?
To clarify, I'm talking about double tenons here, and let's say through tenons. These puppies aren't going to be moving around given the weight of the top of the bench on the arms, legs and feet. I doubt that either vibration or wracking is going to be a problem sans pins, so are they not necessary? I guess I mean with or without glue, too. I'd probably glue the joint, if there were no good reason not to.
Also, I'm not asking about horizontal joints - without gravity helping out I think drawbore pins would definitely be helpful to keep a horizontal joint together.
What do you think? Ever had an issue with a vertical mortise and tenon joint and add pins to solve the problem?