I'm trying to imagine what someone would use it for/want it for. It seems juat like more plastic crap for the landfill.

According to Engadget's coverage of the first model with the touchscreen case, the case mostly just lets you use functionality from the app that goes with the earbuds without actually going into the app. I don't use the apps for my earbuds or headphones, so I can't say how useful quicker access to their functionality would be.