Because you, of course, decide what is allowed to matter to people. 
Sure, he's dedicated his life, to this point, to playing basketball, but I'm sure it won't matter if it's taken away from him in the prime of his career.
Obviously, it's not the same as having one's child killed or being paralyzed, but there are levels of a "ruined" life. A divorce can "ruin" a person's life, even if you would consider that pathetic (it's not relevant whether you would consider that specific example pathetic, the point is that different people base a great deal of their happiness on different things).
Wishing/desiring harm on players to enhance your entertainment (basketball events) is relatively twisted. Of course, we all have our quirks.