A part of me thinks Telltale wanted people to like Carley more than Doug. In his final stats screen, it can show a message saying "You told him he was a weird guy. You weren't wrong." He accomplishes so much less than Carley, unfortunately.
Alarm system, albeit quite useful, the watch can handle that. Plus, wouldn't you have to constantly go outside to fix the wire? One walker getting tangled up in it is all it takes, and that's extremely easy for a walker to do.
The laser pointer. No real complaints here, i prefer this to the gunshot, actually. Either way works.
The remote control for the TVs in episode 1. Again no complaints.
That's 3 things Doug's got going for him. He saves Lee's life once, compared to Carley who does it 3 times, among others. A gun can be used in a truckload of situations to save lives, and Doug admits that he can barely do anything because he simply doesn't have the supplies to do so. Carley also knows Lee's past and gives him a chance to tell everyone about it, whereas with Doug Lilly spills the beans and relationships are strained.
Doug was a cool guy, but we shouldn't be surprised that most people save Carley.