Why concede three point shots?

I watched a university game last weekend that was decided when one team made three three point shots in a row. This made me think again about how most players and coaches want to defend three point attempts. Basically, they back and drop their hands the first time the ballhandler fakes a drive.

This doesn't make any sense. Let's look at the following facts (I think they are facts). The ball defender is the only player who can stop the three. There should be help if the offensive player drives. It's takes effort but it is straightforward to take away the ballhandler's strong side. Made threes are a big boost for the offensive team. Three point attempts tend to have longer rebounds which means that the offensive team has a better chance of getting them.

And yet.....

The reality is that you can't stop a good player completely by yourself. Players can go left, right or shoot. The ball defender can, at best, take away two options. I suggest that taking away the strong hand and the three point shot is the best option. Defenders away from the ball help if the ballhandler drives with their weak hand.