I agree that keeping mites under controls is tricky at best, but I've never heard of anyone using a pesticide. Normal practise, even for commercial beekeepers is to use oxalic acid. That's not really something mites become resistant to. The other option is brood control, where you basically do a period of time with no brood, leaving the mites without the ability to reproduce. I can see the later not being tricky for commercial beekeepers as that is a lot of hives to manage. The same goes for removing drone brood during the summer, it helps a lot, but I wouldn't want to do it to hundreds of hives.
More and more I feel like the right option is the breeding of mite restistant bees, but that would entail doing nothing for a long period of time or crossing European honeybees with Asian varieties that can remote the mites themselves. The work is already being do, but it's still years away. We have found wild beehives, including abandoned beehives, which are fairly mite resistant.