Sure, for the same reason that I have a vertical mill in my basement. It'll never break even, but it'll always be fun to hold up a part and know that I, and I alone, made it.
I have a mill and a lathe. These are wonderful for one-offs. With an injection mold I first need to create a mold and then the object. I just don't see the point (apart form maki9ng hundreds of the same object). Why not create the object directly? Afaik injection molding has even more restrictions compared to subtractive shaping (I've seen amazing things done with the latter).
Making dozens or hundreds of the same object is the point. The example army men from my linked article is a good one-- I could probably make hundreds of them on my creality, but it would take less time and the end product would be smoother injection molding them.