Why don't people set there cold air intake systems like this?

Ok, the purpose to a CAI is to bring lots of air and cool air to there engine and have it induced into the engine via shortest route. People put boxes around the air filter to block engine heat and keep water away. Which isn't much of a problem for the water part if it's under the hood. but, others route it through the wheel well colder air consumption is achieved however water being sucked in becomes an issue. So, why don't people route an A/C duct from the inside of the car to cool the air and bring the inlet of the CAI closer to the firewall which would make a shorter route to the intake manifold or, even route it between the fender liner to really keep hot air out and water out as well. Maybe a lot more work for a Naturally aspirated set up. But, if your going all out by turbo charging it would be more logical. A way to avoid climate control issues with in the cock pit during different seasons would to route the duct front either the the floor or top end of the climate control. This way when winter comes you aren't blowing hot air in. But, it's cold outside so, it's not as need plus water freezes in cold temperatures. Just a thought why would this be a good or bad Idea. I think it would be a good one.