To my knowledge, C4D is popular because it has the easiest user interface for the task. The program itself is build for both
abstract and non-abstract models in a pretty basic way compared to most other programs. Though i don't have experience
with those programs, what i do know is that it is sub-par as far as creating non-abstract models but well capable of creating
the general c4ds you see/use. In other terms, c4d is easiest but most 3d modelling programs should be capable of generating
typical abstract outputs. If you're looking for freeware there is none as competent as C4D (which is among the cheapest as
far as modelling programs go) but i believe that "Apophysis" (program for creating abstract fractal renders) is free, and i know
that both Heretic and Lobb have experience with it if you're interested.