I'm fairly confident in saying that self-expression is the #1 motivator here and the commercial offering was an afterthought.
I don't have a marketing degree, but I'm pretty sure that if selling your software to professional businesses is the goal, making the non-commercial version feel extremely unprofessional is really not the best way to do it, considering most people are likely going to find out about the project's existence by seeing it, and it won't leave a good first impression.