I suspect they're trying to exploit behavioural science.  They want the public to subconsciously associate words like "network", "signature" and the notion that it's supposedly for "everyone" with their brand before Joe Public hears people like us using those words or phrases in connection with Bitcoin.  People will naturally assume it's all the same stuff if we're all using the same terminology. 

They're not hoping people will think "I want a Visa card".  Most of them already have one.  They want people to think "I'm already part of a network that lets me connect with everyone else, so I don't need any other networks that basically sound the same as what I already have".