The idea of a plastic straw ban is a really good one, so long as we know that whatever replaces plastic straws has less plastic. I really disagree with the idea that banning plastic straws is useless under all circumstances. For one thing, as others have pointed out, plastic straws are in many (but not all -- thank you scarlet, and I'm not being sarcastic) cases unnecessary, and people should be aware of how much waste they are producing on items they use for literal minutes. That waste, in many cases, takes centuries if not more to degrade. Second, bans (and discourse around them) like this make people aware of their consumption patterns, which is more likely to stimulate change than the absence of those discussions. As long as people who drink using plastic straws, eat using plastic forks, etc. don't stop with those small first steps but instead continue to cut other wasteful parts of their daily routines out of their diets, it's totally worth that first step. People who get defensive at the idea of these bans (or the absurd reductionist notion that "one person's individual plastic straws don't make a difference" as if that was a relevant or meaningful scale to think about these things at all) are really not being helpful and are missing a great opportunity for some very easy introspection.
But, I also agree with the sentiment here:
Starbucks:
>Bans Plastic Straws
>Still Uses Plastic Cups
Really, all single-use containers should be banned and people should carry around reusuable containers of all types with them wherever they go. It can even be something as simple as an old peanut butter jar in a can coozie. If you don't have a reusable container, and there are no in-house mugs to use, then you can't drink your coffee. I think environmentalist who drinks Iced Coffee out of a plastic cup is a fraud, regardless of whether or not they use straws.