I'm done wading into Puddles (lol) but just to clarify for anyone else who might seriously buy into this, people have died from doing Meth who did not take it to kill themselves. So there's no way Walt isn't responsible for the deaths of innocent people, and that's without even taking the planes into account, which I consider him directly responsible for, but there's still a few "steps" away so I can see how some might not.
People who want to do meth will do meth. Walt just supplied a product for a which a clear market existed. Blaming him for incidental overdose deaths is like blaming a paragliding tour company for someone steering into the side of a cliff.