Not everyone lives/works in an environment that is a climate controlled, indoor space. Personally, I am medically retired, but pretty much my entire working life was spent in inclement weather, extreme hot/cold, or places where it would be easy for your phone/tablet/laptop to be exposed to drops in snow/water, light rain, whatever. The water resistance may not be a selling point for you, but is is high on the list for those who work and or play in extreme environments. Heck, even the printer I carried at work in my truck was lightly rained on a few times.
I dropped my flashlight in my driveway at the beginning of winter in 2014 without realizing it. I lost it in the snow. I plowed snow along that driveway all winter, not to mention pulling my truck with trailer and heavy equipment up and down that driveway all winter long.
Spring thaw came and I found my flashlight. Clicked the tailcap switch and the thing turned on, good as new. Cosmetically it... had character, but I still use that flashlight to this day.