These critics cannot be any more wrong. Swimming requires more thought and focus than many of the common sports others play. True, you don't contend with a ball, nor do you need to devise strategies and plays involving other people. Resistance through water is a factor that is much more significant than resistance through air, and any little error can add tenths that build up over the course of a race. You must feel where your body is in relationship to the water, and there is always, always something you are doing incorrectly.
Swimming becomes an intricate dance of perfecting one thing and discovering another that is flawed.
Even the best in the world, the Olympians and world record holders, are forever looking for minute adjustments in their technique to drop mere hundredths from their times. This quest for perfection involves endless repetition of unimaginable drills to discover the right niche for each athlete. You must always be thinking about what you are doing, feeling each element, to detect the flaws. At the same time you must be thinking about starts, turns, finishes, pacing, and racing. You must be smart to be a swimmer.