https://tectonic-typesetting.github.io/en-US/ declares in the section “About the name” that this is entirely deliberate. I like the rationale and agree with it too:

> The name of the project is “Tectonic,” spelled and pronounced like a regular word because it is one. Enough with the cutesy obscurantism. In cases where the name might lead to ambiguities, it should be expanded to “Tectonic typesetting.”

> If you’re feeling expansive, you can interpret the name as suggesting a large change in the TeX world. Or you can think of it as suggesting a salubrious offering for weary TeX users. Either way, the root of the word does go back to the ancient Greek τέκτων, ”carpenter,” which Donald Knuth — the creator of TeX and a devout Christian — might appreciate.