H.3003 is a bad law because of the things it takes away in the process of allowing open carry. It's always easier to fixaproposedbill before it becomes law, and it's better to shoot down a bad bill than to pass it and cross your fingers it'll get fixed.
Maybe you think Obamacare will be fixed now that it's law as well. :quirky
A poorly written open carry law would have essentially zero affect in the triple murder in Cowpens. These people were in their home, where they can already lawfully open carry if they so choose. Maybe more to the point, most people recognize that a shotgun is a superior home defense weapon, and your precious open carry bill doesn't affect shotguns in any way.
If you're going to cite an example of why we should have open carry (which we absolutely should), find one where not being able to open carry may have made a difference in the outcome. This example fails to do that.