As software engineers (especially ones who work on forward-facing user interfaces), we are taught to think about usability. Many of us are not good at it - including me (though I'm making a conscious effort to get better about it and "think more like a user"). Large companies, on the whole, have mastered this because they can expend huge amounts of money on research and focus groups to study what people want and how they interact with their software. Apple is a master at this. And, this is why the GIMP is terrible to use when compared to Adobe Photoshop. Oh, sure, the program itself is perfectly capable, but the interface was clearly designed by an engineer and not a graphic designer.
The other approach is, of course, to separate the engineers from the UI design people. In a company the size of Apple or Adobe, I'm sure this is probably what they do. But small to midsize companies simply can't afford to do that and, even if they could, somewhere along the line some engineer has to interface with the front end code.
But thinking about the "user experience" is not just related to programming - any industry that has to deal with people who are not native or fluent with that industry can benefit from trying to "think more like them."
The hotel I'm staying in for OSCON here in Portland, the Doubletree, is a good example of this. When you exit the elevator on the fifth floor, there is the standard sign that rooms 500-520 are to the right, and 521-541 are to the left. The room numbers are not on the doors - they are on small plaques next to each door. But, the plaques don't uniformally face the hallway or face in a uniform direction - some face the way you are walking from the elevator and some, strangely, face the opposite direction so that they will never be seen unless someone is walking from the opposite direction as they would normally walk when looking for a room.
Think about this for just a second. The time when those plaques are needed the most is when someone is first finding their room, and they will almost always be coming from the elevator. After that, you usually remember, generally, where it is. In order to see half of the signs on the floor, you have to turn around and look behind you as you are walking.
To add to this, think about how you would normally look for a room in a hotel. Do you go all the way to the end of the hallway? No - you probably stop about 10-15 feet from the end if you determine that your room is not one of the remaining ones. So unless you are paying careful attention to the plaques on the wall, there is a chance that you will not ever see your room. This is the reason I spent ten minutes walking up and down the hall trying to find my room: it was at the very end of the hall with a plaque that was only visible if you were walking the opposite direction.
Now, it's not like this breaks my entire world. I found my room, put my stuff down, and went out for a beer. But when looked at through the lens of usability, which software engineers are very familiar with, it could certainly use improvement. I'm sure the design makes perfect sense to the building architect and to all the people who work in the hotel. But to a guest, it makes little sense and requires extra time spent looking for their room.