The problem here isn't only a module-writing one. It's a GMing one.Here's the problem, and it's the direct opposite of the hammer/nail. When everything is a nail, the only tool players will use is a hammer. When every monster in every 4e module exists only as a combat blob, yes, the players are always going to do nothing more then "Initiative, attack!" When monsters are written to be incapable of doing anything but dying on the players' sword, then the players will - rightfully so - assume that's the entire purpose of all the monsters.
Kalarel has a spy in Winterhaven. Ignoring how hilariously obvious that spy is, what can the players do with her? Well, they can kill her. That's it. There's no convincing her to switch sides. There's no talking to her. You can't trick her out of giving more information then she meant to. You can't spy on her and watch for her communicating with Kalarel. We don't even know why she serves Kalarel in the first place.
The 4e rules give ample support to turning spies, interacting with monsters and so on. If players of the module try this sort of thing and the GM says "No you can't" then it is the GM's fault if the players do nothing other than attack. Of course, a well-written module will offer the GM some support for this sort of scenario. But just because the module doesn't offer that support, it doesn't follow that players can't do anything but fight.
When I ran Bastion of Broken Souls, the PCs ended up befriending the imprisoned god after persuading the guardian angel to let herself be killed in order to open the gate. When I ran the Chamber of Eyes from Thunderspire Labyrinth, the PCs ended up negotiating with the duergar slave traders to ransom the slaves (on the theory that this would save them the hassles of having to find and invade a duergar stronghold, and thus be cheaper and easier for everyone concerned). The modules don't provide for this sort of thing because they're poorly written modules. But that doesn't mean that it can't be done.