That could go up on the "dumbest things you've seen on this site" thread.
The timing and athleticism you need to regularly get chase-down blocks is ridiculous. You can get lucky once, but it's way too easy to jump too soon, too late, or foul in the process....not to mention the speed and hops you need even to be there.
If it was the "easiest shyt to do", then it would happen a LOT more often and wouldn't be highlight reel material every damn time.
Cherry-picking is bad because you're leaving your defensive responsibility.
Chase-down blocks only happen because you were ON your offensive responsibility.