You just put so many psychiatrists out of business

The amount of people addicted to caffeine who don't even know it is crazy high.

The costs of withdrawing for some are higher than others, so for these people quitting isn't just a day or two of headaches, and possibly their life doesn't afford them the luxury of going through the pain and low productivity

Many factors play into it rather than just low self control, in case you're wondering why you got down voted.

Self control is a road to many abilities, some of which are considered unnatural, such as not drinking coffee. My personal favorite is to connect to points in space time together, to create a hole to crawl from one side to the other, for example, to connect the university of Tubingen and Boulogne-sur-Mer.