Dmitri, you seem to have a common human tendency to transfer your personal experience and opinion in to universal,declarative statements. I always have to check myself to make sure I am not doing this and do not always catch my own error. It is best to talk about one's own experience and observations, without making general statements.
You many be trying to "burst poeple's bubbles" but you will not succeed. You have your experiences and other's have theirs. I am not saying your opinions are not valid. They may be for you but are not universally applicable.
Clearly some of us have lost weight riding our ebikes. Saying something in an affirmative manner does not make it true. You say you don't see anyone losing weight. Just read the our stories in this thread and you will see just that.