This is a prime example of how gambling could ruin any career if greed takes over and self discipline is mismanaged. The Detroit Pistons was reportedly ready to offer Beasley a three-year, $42 million contract and he blew it, possibly permanently if his proven guilty of this accusation.
There could be several reasons aside from persona greed.
In movies I watched, most players do this for people in their neighborhood or for family. He tells them to bet on him to carry out an event during the game. It almost felt like that was movie but in reality I wont be surprised many players go with this flow. Well until there is concrete evidence against him, once proven he should face the consequences just like others who did in the past.
Assuming that he is found guilty and what you said happens to be the reason why he would cheat then I will say it is stupidity in the highest level, to sacrifice a multi million dollar career to give family and friends bet tips that will ruin his career. It doesn't make any sense for somebody that has so much to loose to involve in cheating, it will be 'penny wise pound foolish ' like they say. If he's tried and found to be guilty let him face the music. I wouldn't say that gambling ruined his career if found guilty it will be foolishness, it is people that gambles irresponsibly that we can say that gambling ruined their businesses or career because they can go bankrupt.