Because it really isn't just me. If you go through the forum there are a lot of people reporting the same or similar issues. There are people reporting problems with the heart rate, accuracy of the various calorie measurements, "Stand" hours, and so on. I woke up about 90 minutes ago and spent 10 minutes cleaning up the kitchen before the top of the hour and once again - no credit for standing up and moving around for TEN minutes.
If all of us just ran off to the Genuis Bar, how would any of us know that we're not alone in having all sorts of problems with these things? Watchgate seems to be a real problem - whether it's been tattoo-gate, wrist-gate or just plain watch-gate, these things got issues, just like many other new consumer electronics problems.
Here's one other reference I found to the EXACT SAME PROBLEM in less than a minute of searching --
Re: Inconsistant Results: Workout/Activity/Exercise
It's the same problem - "net" calories that don't agree with other sources or with mathematical models. Do we all have the same hardware problem? Because if we all have the same hardware problem, Apple has a bigger problem on their hands than if some programmer (and I'm a programmer) made a coding mistake.
So, thank you very much for your suggestion. I'm not just going to run off to the Genius Bar until I have a better idea of the scope of the problem so Genius Bar Dude doesn't tell me I'm imagining things or I need to turn my watch into a tourniquet or "no one else has reported that to us."