If you are unwilling to read a features list or otherwise do not believe it, there's not much I can do to convince you otherwise. I'm sure the already released iOS 8.2 update with these said additions in the build logs wouldn't either.
I hate to be blunt here, but things in features lists and press releases/videos, you know - the things that a company like Apple is telling you "this is why our product is better than the others" isn't just water cooler talk. People would sort of get uppity about such things if they weren't there when the product ships and they plunked down $400 on it, and hands on tests show everything they are advertising in the device as being there.
How well it will work in regards to health will be a personal judgement to make, I imagine, but what they have shown thus far is a big step over what the competition is offering. It's (nor is any other smart watch) by no means
a replacement for a good MD, and none of them are billing these devices as such. That being said, the tech minded medical community is showing a lot of interest in things like HealthKit.
I've got no personal interest in any of them for my own health tracking, but as a person with a severe amount of diabetes (among other things) in my family, I am very eager to see these devices and how they might improve health tracking.
Apple Watch is by no means an "MD replacement", but it's got a lot of health aware people very interested. How smoothly it'll all go with the FDA remains to be seen, I suppose, and I'm curious how smoothly app approval for the Apple Watch will go. I admittedly don't have terribly high expectations for the first Apple Watch, simply because first gen Apple devices tend to be weak. Until any of these devices get better battery life and actually become stand alone devices that don't still require a cel phone to get things done, I suspect they will remain wholly niche devices.
http://www.macworld.com/article/2881299/apple-watch-might-be-the-ultimate-health-tracker-with-medical-apps-on-board.html