Because it would be used as a loophole to hunt at night with a spotlight. In the old south park episodes they used to do a bit where you could hunt anything you wanted as long as before you shot it you said "It's coming straight for us!" so you had a self-defense excuse. Loopholes will be used.
It was outside of bear season. We always suspected that he shot it first, then dragged it in front of his truck to hit it. We'll never know.
I dive for lobsters. You need to measure them before you put them in your bag. You can't put them in your bag and measure them later and release the small ones. The reason is if you could bag first and measure later, people would use this as a loophole when confronted by wardens with undersized lobsters. Similar regulations with fish and open alcohol containers while driving.
I say I dive for lobsters... I do dive, but I have yet to actually catch one! I caught one out of season just to practice, but put it back.
In Texas it is legal to spotlight wild hogs (on your own property). Even without a hunting license!