To be honest, I was never a fan of straws - never liked to use them, but because of my fondness for fizzy drinks my dentist tells me to use a straw because, when sucked through a straw, the sugary liquid bypasses most of the teeth and goes down the throat - more or less. It definitely bypasses the front teeth anyway. Less fillings overall. 

So, I use them all the time now when drinking Coke, or even chocolate milk or orange juice.

When I'm at home, I don't throw them out the window. When I'm out I don't throw them on the sidewalk. 
I don't see what the problem is with them, personally.