That sounds like something important for me to know about. Why?

The reasoning would go something like this:

1. FAI is, these people say, an insanely hard problem.
2. Insanely hard problems require insane amounts of time/dedication/effort.
3. The author of this has clearly spent a ridiculous amount of time reading/watching/consuming media.
4. You can't both spend a ridiculous amount of time consuming media/writing fanfics, & a ridiculous amount of time working on FAI.
5. Since I am observing the former, I can infer the absence of the latter...
6. If they aren't working hard on FAI, why then should I donate? (Their work is entertaining me quite a bit, yes, but I don't donate to every blog I read.)

Alternate, more fallacious version:

1. FAI are Serious Business.
2. This are not serious person.
3. Therefore, this are not FAI person.*

Now, as for Reddit: I fear to reread the fic to get specifics, but I remember thinking at least twice reading through it, 'isn't that a reference to an obscure in-joke or article I've only ever seen on Reddit?' Whether those were truly Reddit refs/Reddit-reading-sourced or not is almost irrelevant.

EDIT: * I hereby dub this a 'sylolgism'. Go forth and plague the people with fallacious proofs written in lolcat.