Halcro,
You stopped at the first terminology you didn't understand! You only read the first sentence! Please keep reading the article, it's very informative.
+++++ what you speak.........any 'not so well executed' wall shelf (and can you please describe what you mean by this as I can't even imagine?)++++
Well, it's very simple: a 'not so well executed wall shelf' means a shelf mounted on a wall that has not been designed and constructed taking into account static and/or dynamic loads. In fact, it is actually a good idea to talk to a civil or structural engineer and ask him or her to do the calculations for you since we're dealing with probably 150 lbs cantilevering off of a wall. It's a very simple job and they probably won't charge for it.
Halcro, this is not a discussion about my 'wall shelf' can beat your 'floor mounted stand'. A fellow audiophile asked a question and we are simply providing our opinion about it. It is ok for somebody reading this post not to agree with me or not to agree with you. It's called 'freedom of speech'.