Switches that open the neg.

Sorry for not saying hello first.

Hello, all.  I am most definitely a noob, this being my first post.  After looking at different diagrams and schematics, I have noticed that a lot of inputs open the negative side of a circuit and not the positive.  I am curious as to why this is.  Higher voltage circuits never open a grounded or grounding conductor.

Welcome to the forums.  Ground switching actually keeps arcing across the contacts of the switch to a minimum.