There are some absolute advantages to having low humidity:
1. Bud rot, Root rot, almost any kind of rot, mould, fungus - forget about it! With low humidity, you almost have to try to get these things!
2. Swamp Coolers are a double bonus. No, make that a triple bonus! They are way cheaper to buy (or make your own, DIY). They are a hell of a lot cheaper to operate. And Swamp Coolers not only cost less than regular A/C, they also add humidity to the air as they operate - not to mention that they contain a powerful blower for air circulation - so I guess that makes them a quadruple bonus! If you don't know what a Swamp Cooler is - just Google "swamp cooler" - it's an "old technology" air conditioner that only works in areas that have low humidity!