I'm not so sure, yes the mods are pretty anonymous on the bigger subs, but they do a tonne of work and have a tonne of experience on how to actually moderate the subs. There's a whole host of rules that have grown up around each of these communities that have been learned through bitter experience. So sure, you might not notice tomorrow if /r/pics moderators all got replaced, but I guarantee you over the next 6 months the sub-reddit would change in character significantly.

You can employ paid moderators, I don't think it's a terrible idea from a quality of user experience perspective. It's an awful idea from a "We're desperately trying to get this fucking company to IPO".