Trends are hard to define.

The entity behind Kitties has some other high profile projects and media contacts. If they have something interesting to talk about, they can get people talking about. And even with a large staff of their own + friends - their incidental social network alone is enough to start some yammering.

I don't think a bad project can go viral, but many viral worthy projects simply don't go viral.

Also collecting kitties appeals to more people than collecting punks.

Indeed I want one but all the ones I find cutest are expensive.

I think https://www.cryptokitties.co/kitty/102 this one should probably just be put out of its misery

I dont think thats it though.

i think its something to do with the breeding