The chance is higher that the player says "lets get to the first poi, finish this last few percent and get world completion already".
What is the point of going to WvW without contributing to your server's efforts? People would play WvW if they already have some interest in it, there is no need to nudge them. In this case, they are nudging people the wrong way. If they really want people to WvW they should make a real WvW title that encourages people to work with their teams and take down objectives, not run in random directions depending on which poi they still need to discover.
With the current system, I don't see how the achievement has met its goal to make peoou're ple interested in WvW. I have 99% world completion now without even knowing what the supplies are or how to use them or having ever worked with my team. I am sure I can get the remaining 1%, just by server switching and tagging along, without taking down a single keep. What if I got my star, does it mean I did WvW? I think not.
You're right...your star wouldnt mean you did WvW...it would mean that you completed the World Exploration achievement. What does that have to do with your original gripe about not having to do WvW in the first place?
Look guys, lets just all sign a petition to ANet that states that anythign Daesu thinks is broken needs to be fixed, regardless of what it is. If Daesu doesn't like it, that means its broken and isnt working, despite the fact that many other people have completed it. It's still broken, and those that completed it while broken are lying or magical mechanics of gaming.