The ship was born and bred in the nsfw zone of the Sonic fandom (as so many other crackships have, of course).
But this one in particular, as the other anons pointed out, truly barely exists outside the nsfw part of the fandom (as they said, KrazyElf stuff barely manages to stay out of it, and if you see it, even then, you might still question yourself if you can post it in a blue board).
It shows you how that ship, unironically, has nothing else going for it (but that's an issue many ships of its kind in other franchises has).>I honestly don't know why, and to this day I don't understand when did that ship gained so many followers.
It's Sonic, there is no explanation for a ship, back in the day, I saw fujos shipping Tails X Metal because "Tails likes Sonic and machines, obviously".
Still, in this case, I say the main responsibles are Bigdad and Michiyoshi, plus that one Sonicfag who has commissioned 90% of the artwork from other artists. Bigdad with his amazing Rouge redesign (funny enough, his only Sonic redesign I truly like), which everyone started copying, thus leading people towards his art, and you know the math:>Sees nice art>Likes nice art because art is nice>Sees nice art
's content>Likes nice art's content because art is nice
Michiyoshi because of his doujin work which gives this strange "official" feeling to it. It's not just a fancomic, it's a Japanese fancomic, and not only that, but it is a doujin that is sold physically.
As for the rest of the artists, Tails has slowly, but steadly, turned into the default guy when they want a quick partner for Rouge for the sex scene they are drawing.
10 years, they would have debate themselves between Knuckles or Shadow (provided they don't ship her with either, or an alternative crackship).
Now, they don't even necessarily ship her with Tails, but either know it tracks people, or laugh at its meme potential.
Anyway sorry for the long paragraph, I'm just procrastinating something I ought to do.