If you happen to catch an artist at the beginning of their careers, and are willing to take a chance on them, then this might happen but more often than not it won't.
Also, as a collector you actually want artists to be successful so you want them to be growing and continuing to get more recognition and keep producing work. In order for them to do that you want them to get better and better value from their work.
The artists mentioned here might not have done so well in that auction but they certainly went on to very lucrative careers.
I'm not sure what you mean by that.
If you mean the value chain of the gallery/dealer/auction world is where prices go up then yes, that's true, but the artist is very much participating by creating and selling new work. In the $750 -> $40K+ example the artist will definitely get a lot more than $750 per piece in the future.
If you mean art only gains real value after the artist is no longer making any (i.e. is dead), then actually that's not true for contemporary art.