I have a great deal of respect for this line of thinking. Life gets more and more complex as we accumulate tools which keep us more constantly accessible and provide more constant connectivity. Increasing demand, decreasing down time.
However, the conclusion that an Apple watch is one (more) screen too far isn't what I have found from personal experience. Quite the contrary. What the Apple watch does for me (and the Pebble to a lesser extent before it) is to give me essential information in a form which can be gathered in a quick glance and minimal interaction rather than the more time consuming distraction of a larger and more complex device. The watch - and really any viable smartwatch with broadly similar features would do - is my triage point where I can quickly and easily identify what needs to be dealt with immediately, and what can be left for later. It has made my life considerably less cluttered by demands and much easier to prioritise.
For me, and I think a lot of people in similar situations, the Apple watch isn't a tough sell at all, it's a solution to a growing problem. However, to others, it's at best a solution looking for a problem, and understandably a tough sell.