Good thing about a kettle as opposed to a wsm is they do just fine in the rain.
Yup, they do. Reason is, IMHO, the kettle lid has the overlapping lip to the body, so no water gets down inside. The WSM is just the opposite, The lid sets inside the lip of the body, letting water seep in. Just my opinion.
as I understand it, the WSM is designed that way on purpose. It’s designed as a water smoker. If the lid overlapped the body, you could have smoke laden condensation dripping down the body.
I don't know the science or thinking behind the design of the WSM. What you say makes sense. All I know is, I NEVER use water when smoking in ANY of my smokers. My 18" WSMs never see an ounce of water, not even in the water pan. The water pan is used as a heat baffle, filled with wadded up aluminum foil, then covered with a sheet of aluminum foil, installed with a slight dish to catch the drips. Been doing it like that for years with grate results, never any issues, and no messy cleanup. Water + fire = steam. Nope, not 4 me...