It seems to me like even the most naïve model of plate tectonics is able to produce more convincing heightmaps than conventional fractal based methods. That's why I'm really wondering why it's not used in more projects?
Fractal-based methods are often used because it is fast enough to be computed on the fly for procedural terrain (see Minecraft). For extremely large scale terrain you simply can't have all of the terrain in memory (see I-Novae). This is the main reason why fractal-based methods will continue to be very popular.
Your work looks awesome. I don't have time to read your thesis though. Do you have any rough numbers on how long it takes to simulate and what resolution height-maps it can run in reasonable time?