I've grown to hate it because it's another example of people fixating on a number as a measure of their success or failure, either during a workout or throughout a week. Worse, the people for whom these numbers become important lock onto them so much that their mood for the day is dictated by these stupid numbers, whether their on a scale or on a watch. There are folks out there who weigh themselves 2-3 times a day - and when you suggest they try going without getting on a scale for... say a month - they tell you they can't. They can't stop. Or they do a strength-based workout, focused on quality movements and heavy lifts of 4 repetitions, with 2-3mins of rest after each set. And maybe they even set a personal best on a lift, but then they look at the stupid watch and say "Oh, but I only burned 100 calories. What a shitty workout" and they leave feeling uninspired and lazy.
This is not okay.
If you read this, and think "Oh - I've said that" then please, re-evaluate. Focus on something other than a number - focus on an achievement. And then train for that. Stop basing your sense of accomplishment on an arbitrary number that can fluctuate based on external influences beyond your control. Instead, set your sights on experiences, where the journey is as much of a reward as the "finish line".
Train to live.