The idea that passive voice is used in philosophy doesn't seem to be a novel idea [0].
For what it's worth, I don't think undergraduate CS degrees develop students' writing abilities at all. There are only a few proof-based courses I can think of, and those courses (e.g., Theory of Computation, Algorithms) need not necessarily be taught in a mathematically rigorous manner (which is to say, proof writing in these courses may be minimal, depending on the instructor).
For what it's worth, I don't think undergraduate CS degrees develop students' writing abilities at all. There are only a few proof-based courses I can think of, and those courses (e.g., Theory of Computation, Algorithms) need not necessarily be taught in a mathematically rigorous manner (which is to say, proof writing in these courses may be minimal, depending on the instructor).
[0] http://wehaveneverbeenblogging.blogspot.com/2010/02/on-activ...
Edit: grammar!