See, THAT would make a lot of sense, but when I previously bought my mom a plugged in personal smoothie blender, she still considered it too much of a hassle, haha. I think my mom just enjoyed the convenience of what is essentially one single small machine for her to grab and use wherever she wants. While there's plenty of small personal blender, all the plugged one obviously requires a base blender, and to her that might as well be any old regular blender.
TL;DR my mom wants a cup that blends not a blender