Sure. I'm not saying I am a professional. I'm saying I will provide professional-style support (according to the connotation), just not necessarily in a timely fashion, and it's demoralizing when other people say you should avoid my amateur software because they're leaning on the connotations of "amateur" and "professional."
If you are making products that people can rely on primarily because you enjoy it, you are literally an amatuer.
There are figurative connotations of quality and polish implicit with those terms, but I find those connotations unfortunate and in many cases unwarranted.