For something to be truly interactive, you need a degree of freedom. The video game medium is, inherently, about interactivity. Open world games are better suited to accomodate higher degrees of freedom and thus, interactivity. Therefore, it is not terribly out of line to think that there is something 'better' about open world games when compared to linear products.
However, most open world games don't live up to that promise. Or my idea of what they should be.
Disclaimer: I fucking loved the way Alan Wake turned out.
thing is, you aren't disagreeing with me. while on paper and in your imagination, open world games should always be better, the end products aren't very regularly... so if a developer switches to a more linear design, we shouldn't be presuming that it's 'dumbing down' the game. like i said, there's nothing inherant that automatically makes an open world game better than a more linear one.
i love GTA4 for example, love it love it love it, but RE4 is still the best game ever made and if anything it's less linear than the earlier Resident Evil games (and less linear than Revelations somehow, despite revelations weird chapters and cutting from one place to the next).
until someone figures out how to have a story as well put together as Alan Wake in a more open design, i hope both types of games stay around.
Alan Wake PC looks better than most PC games I can think of. thus my lack of surprise to find it's a demanding title... of course people just want to cry 'crap port' and 'ruined by consoles' irrespective of the facts. but oh well.
on performance, remember to hit 60 fps at 1080p you're talking about pushing eight times the pixels of the 360 version. furthermore, we're adding effects and not rendering things like the fog at reduced resolution. so yeah, ten to fifteen times more powerful than Xenos to approach 60 fps at 1080p with the settings cranked isn't really that crazy for a game with LOD settings. remember, we're pushing further draw distances and more polygons too.