I really don't understand the logic here. If two players are jumping for the ball, sure there is some risk to both players. It is only fair that one isn't allowed to raise their legs to *defend* themselves at the expense of the other also going for the ball. Why is it *smart* if one player blatantly disregards the rules to risk injury to the other one that is actually following them? That is just dirty...
In hockey, for example, keeping possession of the puck makes you fair game to hits from the opposing team (that's the rule). If the possessor were to raise his stick at the direction of the incoming player trying to make a hit to *defend* himself, I wouldn't call it smart but plain dirty.