You're asking that question to a bunch of photo enthusiasts...
For example, on my next vacation which includes
DCL and WDW, I'll likely bring a dslr, mirrorless, and 5-6 lenses. I may also supplement with a waterproof p&s to actually use in the water.
The reason is simple--- capturing great photos is a big part of the vacation experience to me, and therefore I want very capable gear.
That said, for many people (including myself at times), there is value to lightening your load... Enjoy being in the moment of the vacation more while carrying less gear.
I've done a vacation with just the Sony rx100-- high end p&s. Not as capable as my dslr, but pretty capable. So I could still get some great vacation photos but without lugging around my 10-15 pound camera bag. That's as much as I'm ever willing to compromise -- the waterproof models IMO are only good for actually taking into the water. Their image quality and features aren't worthwhile otherwise.