Damn that's wrong on so many levels...

1. 10sec is likely an average...some spend more time, some spend less.

2. To get the amount of mined hashes equivalent to 10 person staying one hour, you don't need exactly that. What I meant is that small numbers add up, e.g. 10 people can mine 1 minute simultaneously which would wake 1 person 10 minutes.

3. Browser mining is an emerging alternative to the currently existing way of generating revenue off views - advertisements. Either you watch an ad (assume no adblock for now) or mine with a portion of your CPU for 20 seconds - which one would you choose?

You should understand that this is a special kind of coin earning technique before calling bullshit.