Because wolves are cool and cute, and white is cool and cute, and her crow buddies are cool and cute, and until Kagerou showed up there was no other canine Touhou. There are quite a few reasonable reasons. I wouldn't complain, though. She's more popular than a lot of "real" Touhous, but nowadays she's got that awful Awoo Girl bullshit, so it's kind of a wash.
Because wolves are cool and cute, and white is cool and cute, and her crow buddies are cool and cute, and until Kagerou showed up there was no other canine Touhou. There are quite a few reasonable reasons. I wouldn't complain, though. She's more popular than a lot of "real" Touhous, but nowadays she's got that awful Awoo Girl bullshit, so it's kind of a wash.
That's because Ran is a Madam canine who looks charismatic, while in the other side Momiji took the part of Moe canine just like Chen, both being just cute and little~
People like the underdog (ba dum tss) A character that is there, but at the same time isn't there for having nearly no identity through a vague description and only a loose design, is the ultimate Lego brick which an artist can shape into whatever they desire and making them more likeable. It isn't even clear from her sprite if she has canine ears and tail, but just something tagged on, that artists wanted to modify their Lego brick to have, but I'm certain that without them, she wouldn't have gained half of her current fan base.