This gets into subjective perceptions of the detail in question. Mathematically, you are correct that fractals have infinite detail. Visually, however, it's noticeable when you've run out of interesting fractal detail and that the technique has failed to produce more detail (that the brain will acknowledge as such.)
Had they said "fractal detail" not only would they have received less grief for it, but they would have provided us with an explanation for part of their system. That last part seems to not be something they're inclined to do.
The detail needn't be fractal to be infinite though. It could be procedural e.g. a rough surface could be given infinite detail by using a pseudo random algorithm.
Had they said "fractal detail" not only would they have received less grief for it, but they would have provided us with an explanation for part of their system. That last part seems to not be something they're inclined to do.