I would like to see Doug Rainer chime in on this question, since he is a RV tech with 30something years under his belt. This has been heavily debated on every forum, and I have never seen an explanation for it.
I work in the marine industry, and ABYC says put the switch on the positive side. Ever OEM builder that I know of puts it on the positive side, and when I do a 12V installation, that's where I put it. We do it that way because of the possibility of a large current load being drawn through wiring harnesses because of bad DC grounds, but I realize that RVs are not boats, and I would like to hear a reply from someone who actually know why and not simply an opinion or something that was written on the Internet.
