Nothing in particular, but I like the idea of keeping my private information to myself.

It is not just your location data which is collected and profiled but also your purchase history. The combination of these two is more than enough to make a detailed profile of who you are (as in 'what your habits are', they already know your name and address etc.) and whether you have anything 'interesting' on the go (visited the hospital, went to the drug store, bought more booze than your health care insurer thinks good for their bottom line, etc.). Payment processors sell this data to the likes of Facebook and Google who use it to make a more detailed profile. If you're fine with this, no problem, just use that bank card/Swish/Apple|Google|Samsung|whatever Pay. If you're not, cash is one of the ways of limiting your exposure to these practices.