Good question Eddie -
The way I see it, waders are a necessity in mid-summer because even slighter cooler water saps all the heat from the body with time. I recall days of chattering teeth on a 90 degree day after standing in water that swimmers would classify as "very nice" for a couple of hours. If your fishing will involve extended time in the water then they are a must. If you are planning on this type of fishing in between paddling (or should I say paddling in between this kind of fishing) then you probably need waders.
If the structures you plan to fish are land structures like shorelines, points and jetties, I would say there is no need for them. Therefore you would not need waders when getting to and fro.
If you are talking about fishing from the kayak, I see no point in waders at all.
I do not plan to fish from the yak at all. I plan to fish from the places the yak takes me. Many of them are submerged shoals and structures. I will wear waders with scuba boots to allow swimming if needed and wear my CO2 PFD. I also carry a half used roll of duct tape to close the top of my waders in the event I need to swim. Of course one can't anticipate swimming all the time so that's only as good as the situation permits but it beats the heck out just of a wader belt.
On those days when I plan to trek to land structures unavailable to the shorebound angler where I will not be standing in water very long or very deep (ankle deep) I will be indulge in the chance to wear just shorts and sandals.
So for me it really depends on the fishing venue of the day.