I think this theory is not right in some ways
People and friendship should be firm (probably not that word but the meaning is near). And it doesn't matter if they loosers or winners. Also all we have balck and white lines in the life. But i think we must choose people from how long they are with us and how they behave with us
As for topic - I think in some educational or self-motivation communities. I've found there such people that are such activists as me (btw my best friends and my gf are not sooooooo succesesful as I and this doesn't influence on our friendship)