That option is less realistic, in my opinion. Since many of the wiki's are on different servers, often located at different physical points in the Real World.
So, say for example, I sign up for Bulbapedia and have my account at WikiBound link up with this. Bulbapedia's server (which are in Australia) talk to WikiBound's server (which are in Utah of the United States). It simple for that connect, but now image myself trying to do it on 16 wikis - It gets a bit more complicated. At best, it's making 16 connections; at worst, it's making 2.09227899 × 10^13 connections (that's more than 20.9 trillion connections).
Then image 10s of users attempting to do it. Or 100s, or even thousands.
I'm exaggerating, i am aware. But my point is, the servers could get bogged down with connection attempts because of this.