I think they're stupid, but I do have to say it was a smart move of Microsoft to include achievements from the start of the 360 and a smart move for Sony to copy them so quickly. For those that are trophy and achievement whores, trophies tie you to your account for that company and you're personally vested with a ton of points you'll end up losing if you switch over to the other side. While those points don't mean crap, you'll still lose them and start at whatever you have on the other side, either 0 or a low number if it wasn't your main console.
Sony recently released a copyright about getting prizes for trophies and the ability to sell/trade trophies as well as digital products. So maybe being a trophy whore on the PS4 will be a benefit in the future.







