"Is it possible to attain a phd and rely mostly on rote memorization?"
No, but it's possible to just be a research serf to the professor, and the professor will carry you more or less to completion - very little indepenent thought needed. You do need to be able to do lots of (well defined, but tedious) work.
It's a shame that completing a mountain of well-defined, but tedious work with little independent thought is considered an original contribution to the field.
Well of course it isn't, and you won't see any job openings saying 'looking for a 4 year slave'. And you generally hire people expecting them to be capable of working independently. But sometimes it doesn't turn out that way, and instead of losing years of work and effort, things just turn out a certain way.
