It's not meant as an insult. I meant professional as in
>characterized by or conforming to the technical or ethical standards of a profession.
In Germany we use the word to express sophistication and technical expertise.
If you don't know how to handle algorithmic complexity it's less likely you will take a job that demands knowing much about it, but that doesn't mean it's not professionally needed.
What do you mean by, "not working on professional things"? Seems a bit insulting to me?