Those driers tend to be in only a few places like government offices where they are trying to show off.
I've noticed a few restaurants handing out plastic bottles, too. I complain. Oddly, Starbuck's is the one leading the charge here. All these 1500won coffee shops popping up everywhere never give reusable cups and even look at me like I'm crazy when I hand them my cup. They should be forced to discount like 300won or not allow you to collect points if you take the cup.

The weirdest is the Paris Baguette, they give me their reusable cup if I don't leave immediately when I go on a break during work (I can't finish a hot coffee that quickly) and won't fill up my reusable cup for drinking in the restaurant because it is the wrong brand. They are even reluctant to fill it up for take away so I just pour it myself and tell them their customer service policies are backwards.