I've seen it in a product that made several millon dollars a year. I was horrified. You'd be shocked at how far you can get with a product that simply solves the problem no matter the tech stack.
At some level, were you amazed though? I feel like people in places like /r/learnprogramming should be linked stories like this whenever they post "should I learn python or java".
What would someone learn from this which would help them make the decision about which language would be better for helping them understand how to write software?
Maybe it would broaden their perspective of the possibilities? If you can solve million dollar problems even with spreadsheets, then maybe the choice between these two commonly-used problem solving tools is not that big of a deal? Just pick one or the other and focus on honing your problem-solving skills!
I used to work for organizations that used BI software like Qlikview and SSRS. I got an ostensibly non-technical job where the only software I was provided with was MS Office, and I am just amazed at how much of the stuff I used to do with Perl, Oracle, Qlikview, etc. can be done with Access/Excel/VBA.