We feasibly cannot ban adfly. This really would absolutely kill a lot of the creators and would make them go elsewhere, because then they cannot use MCF to get "rewarded" for their content. There is not a replacement that pays as well as adfly that users could use instead. If there was, it'd be better if they used that.
I know adfly is terrible, and I'm one that would love to remove it, but within the impact that banning it would have would have such a backlash that it'd end up being more problematic.
Optifine is an example of this. Banning optifine off our forum would be a huge hit to the modding section. Forge (until recently) used to use adfocus, so this would have prevented them from using MCF (they weren't but that's an example).
It's sadly not something that we can really do without some way to still promote using our site for advertising the content.