That assumes that a significant number of people a) know that Google has a EV certificate and b) actually check it. To the first point, I'm not sure that Google actually does have an EV cert - looking at Google.com, I think they just have a DV cert. And to the second point, I suspect that few people actually check if the cert is EV or DV (If they check that the connection is encrypted at all).

Having an EV cert for yourwebsite.com does nothing to prevent fishing if people are directed to someotherwebsite.com.someotherwebsite.com. So, whats the point if going through the extra pain / expense of getting one?