I’m a PhD student and know more about X than anybody, including my supervisor — why can’t I open an account?
We know that many PhD students are highly knowledgeable and capable of writing Philica-quality articles, and if writing articles were all that membership allowed we would let graduate students join. However, membership of Philica also allows peer-reviewing of other people’s work. It is not normal practice for students to do this to the work of fully-qualified academics, and we do not consider it desirable to change that here.