For the non-Dragon Age nerds. I think I can provide an explanation. In Dragon Age: Origins, the fangirls favourite romance Alistair mentions he has an obsession with cheese one or twice. Somehow the fangirls have turned this into one of his most defining trait when doing fan art of him. As Adam voices Anders, who is QUITE popular (understatement of the bloody century) with the fans and I guess the fans managed to have a running joke amongst themselves that “oh let’s make Adam say stuff about cheese then use the audio in fanvids or something”.
That’s the ONLY way I can imagine that became as prevalent as it did.