You generally don't have ice in your beer. Because ice makes beer gross (I'd like to find the scientific reason why, but it just does). Soda and water are typically served with ice, and it is difficult to drink it without a straw. Especially crushed ice.

Now if you had a lid on the cup similar to car coffee mugs (where the top is indented with a small hole for the liquid to flow through), then that could be a solution for the straws.