Dieting? That's passive: it involves not doing something. All I can think about is the fact that I shouldn't be eating, which makes me think about eating, which makes me eat.
Obsessively counting calories? It makes me do something active: strive for a minimal caloric intake for the day (I say minimal but minimal for me is healthy for anyone else).
I need to do the same thing with reading papers. Reading a paper is a passive activity while writing a paper review is active. I try to find at least one major flaw with each paper I read so that I have something active to keep my attention, a goal.
Saying "behavior xyz is silly" is unfair and not super constructive. Each of us has a single data point of human experience. Generalizing from that is kind of silly if you think about it.
If I could curtail my bathroom activity healthily, and if that would lead to a better and happier life, then dammit I'd track that shit in a heartbeat. Ditto for breathing. And unless you are having an unhealthy amount of sex there is nothing to gain from tracking it (except for ego/lack thereof).
The examples you list above all have something in common: there is no benefit to tracking them. For calories, there is an actual benefit.