From the instructor's perspective, it sounds like you didn't even try to do the intentional assignment (which the fault/crashdump/find info in the crashdump was the most important part), and either did your own thing or sent in someone else's assignment because you didn't look closely enough at what it was. Yes, this is a big accusation, but it happens every semester.
The professor just wanted you to learn what you were supposed to from the assignment, so that you could build off it.
Your cynical take on it now shows that you still don't understand how to teach or the importance of that fundamental skill.
Is there a place for fun, exploratory projects? Of course, and I always incorporated them into my syllabus. But there's also a place for structure. If you want to explore along the way, then that is even better! But you still have to meet the incremental checkpoints along the way, otherwise you have not demonstrated that you have met the core competencies of the subject, as reflected by your grade.
There's a lot of shortcomings in modern university education, but I loved teaching, and would still be doing it today if it paid reasonably. My biggest headaches were the cheaters and the know-it-alls, mostly because neither of them knew enough to respect the subject matter and its importance. The students that made me the most proud, though, were those that trusted the roadmap, and in the end were able to do bigger and better things than they thought that they were capable of.
It's not about extra work. We did plenty of it, btw. We just didn't always tell you about it. The University system referrs to it as "service", and you, the student, are the beneficiary of it, either directly or indirectly.
"Teachers don't want extra work." I'm sorry, but this sounds like a toddler stomping their foot and saying "Mommy and Daddy don't love me because they went to work today instead of staying home to play with me."
I'm glad that you wrote the RPN calculator. That's cool! I'm disappointed that you use this as an opportunity to bash the educator who agreed to take a low salary so that they could help you learn important things that are fundamental to your craft and chosen field of study.