For instance, for companies where programming and IT is not perceived as a core competency and asset, but a cost.

This; in my experience median compensation for programmers is comparable to PMs, and the high-end of programmer compensation is significantly higher than that for PMs.

A programmer high on the compensation scale will typically have decided to stay on the "Individual Contributor" track and top out as a "Distinguished Engineer" or similar title, but still be considered as a programmer. A PM who has advanced to a similar level, on the other hand, is likely to be some sort of VP or SVP and considered an "executive". That is to say the PM compensation track divergers, while the Engineer's stays the same

Let me be more clear: I'm talking about something like an MTS or Senior Engineer, rather than a Fellow or Distinguished Engineer (and FWIW, at many firms, a Fellow/Distinguished Engineer may very well have compensation comparable to a Director/VP).

Only if you are Bruce Lindsay and you invented Joins would it be comparable. Directors or VPs often get quarterly options

Correct. I run a software business. Our top coders are paid higher salaries than any "managerial" roles, by some margin. That said, the managerial roles have more upside in terms of bonuses, but that arises more as a result of how one goes about motivating people with rather heterogenous talents.