I think to a degree that its illegality in a number of countries prohibits its production and distribution; it has been illegal in the US, EU and China for quite a while now, meaning no one can produce or sell it as a legal RC any more. In the EU most other 2C-xs are legal aside from I and B, so that's my theory as to why it's not around. Never got to try it, such a shame... Same with B. I'll have to settle with having known C, D, E and P. Same thing happened with 2C-T-7, it's illegal just about everywhere, so it simply disappeared from the face of the earth. Gotta wonder if there's people out there making/selling these still... One can hope.
While stuff like LSD is still produced illegally, it is much more famous/notorious than something unknown like 2C-I, meaning that illegal demand for LSD will drive production, while no one really even knows that 2C-I ever existed in the general drug using community.