I understand where you're coming from, in that if you're talking about people who talk about their calorie burn you are usually talking about people boasting about their unrealistic achievements while simultaneously making your much smaller but more probable achievements less.
Ignore these types. The benefits of exercise are more than calories burnt. eat less calories to lose weight, exercise for the health benefits alongside.
I think you are correct when you say many people overestimate their calorie burn through exercise, but picking a random number such as 10 calories per minute is as bad! It depends on what you are doing and how much you weigh. A large man working at high intensity could easily burn 1000 calories in an hour, but a 9st woman jogging gently won't get anywhere near that.
Having said all that, YABU to let it wind you up, why does it affect you?
Oh yes me too. I have no end of friends who think a walk around the block will burn off their sunday dinner! Besides, calorie burn for each individual is dependent on so many variables that sports equipment, pedometers etc can never give any more than a very rough estimate.
The bigger you are the more calories you burn. Whether that's fat or height/muscle. This is before you take into account age, metabolic rate and other factors we can't really measure. Calorie counting, although I am a huge fan and have used it to lose 7 stone so far, is not an exact science, more an educated guess.
Standard rate of burn for everyone makes no fucking sense whatsoever. Maybe you should do some research into it before you start slating others for being stupid. Also how does it affect you if they do overestimate. Most people do work out they need to adjust something if it's not working.
I have no idea where some people get their figures from??? Even with sports watches some are way out and have read some quoting 1,000 calories where its more 400! Fed up of reading silly figures on forums.
For some of use fatties who are trying to burn and get fit I would rather work on a more realistic figure. Surely basic figure is 10 calories per minute as a good indicator. Working out for 1hr which is more 45 with odd breaks and rest its max 450 calories.