Every MMO I've ever played, which is WoW / AoC / Rift / WAR for long periods of time and a few others that I gave a quick go have suffered from the 'best server syndrome' of a large amount of people pre-picking a server to be the place to be on launch. 'Full' has never meant 'closed to new players' in any of those as no dev wants to end up telling new comers that they can't play on that place to be or if their friends are already there that they can't play with them.
I think it's a good thing that they ultimately leave it to the players to manage, that if you think Desolation is that terrible to be on with so many people you can go to another server. The developers know this is problematic for something like WvW which is why that is based on a ranking system so the top 1-2 servers are always going to be playing each other and then whoever wins out of the 4th/5th/6th will be joining them.
Plus it came out days ago - no doubt theres going to be change ups as this game goes on, new servers, alterations to how the back end works how WvW works... It's an MMO, if you enjoy it put time into it and know that it will only expanded upon in time - if not check back months/years down the line - if you hate it that much just go about your business and never worry about it again.