I am in total agreement with the code of conduct about homework, and I appreciate that the mods have many difficult judgements to make, but I do think the decision here was rather harsh.
The OP hasn't asked anybody to write the assignment. Asking a primary source for raw data sounds like a perfectly reasonable research strategy - unless the assigment is meant to be for imaginative writing, i.e. you are supposed to dream up possible reasons, rather than discover and convey real ones.
I'm 53 years old, not involved in education (except as a parent) and don't have to do that sort of thing, but if I did, then I'd ask a load of geeks why *they* became one and summarise the results. That strategy seems eminently reasonable - certainly better than ripping someone else's research off the internet. N.B. OP isn't asking for people's opinions about the motivations of others, just their own motivations.
Just my opinion.