Because the two answer different questions. Counza exists because most students in the world have no counsellor at all, and roughly 376 of them share each school counsellor in the United States. Software is the only thing that reaches that number. Plinth exists because a small number of families want the opposite of scale, and are paying for judgement that carries a name.
The line between them is not squeamishness about the technology, it is about what can be held to account. A model can summarise a transcript, surface a competition worth entering, or keep a calendar honestly. It cannot decide that a student should drop the impressive activity for the awkward one that is actually theirs, and it cannot be blamed when that call is wrong. Every part of the work that turns on that kind of judgement stays with a person at Plinth, and that person is me.
The practical commitments follow from it. No model drafts a Plinth student’s essay, activity description, recommendation or research paper. Nothing a family sends is used to train anything. No Plinth file is visible to Counza, and no Counza system touches one. What editing does and does not mean is set out in full on the essay service page.