I agree that touch and goes have a place in flight training, though perhaps a place which is more limited than commonly applied. New pilots cannot, and generally should not be expected to change "modes" so completley, so quickly, particularly when it is necessary to maintain control the entire time. As said, something's going to get missed. That's not good learning. It is not ideal to require the use of a checklist prior to takeoff, and then not allow the time required to concentrate on it. That sends a message that it is not important. That said, pilots do have to be aware, and prepared, should an overshoot after touchdown be necessary for some other safety reason. That is why we test to assure that an overshoot (takeoff) is possible in the worst case landing configuration, in case the pilot did not get the aircraft reconfigured, before getting airborne again.
In particular, touch and goes are not ideal for water flying training. Time on the step is important, but time learning how to get on and off the step is equally importnat, and should not be missed, because a touch and go was done instead.
I have seen too many aircraft touch down, only to see all of the flight controls apparently be forgotten as soon as the ground is contcted. In my opinion, if an aircraft is moving through the air, it should be being flown by its pilot. The fact that the aircraft is on the ground, does not absolve the pilot of the responsibility of assuring that it is moving through the air as intended. Again, a practice opportunity lost in touch and goes. Touch and goes should be stop and goes, where runway length and traffic permit, and otherwise scattered into training, rather than being a mainstay.
Just my opinion...