Why is the industry making it difficult to upgrade GPU/CPU's in laptops? Well you probably aren't going to get a definitive answer. And us as consumers can only make assumptions based on observations. But let's discuss the problems with laptops, and how they are a different beast than desktops:
- Why aren't there standardized sockets on laptops, or slots, or other things we find on desktop motherboards? I could say, with confidence, it's because they take up clearance and prevent low profiles that the world desires so damn much. It's not much, but for instance, if you were to keep that 3mm or less a socket takes up, ultrabooks would be thicker. This isn't a problem with those 17"+ beasts, but then again, they aren't called "desktop replacement" for nothing.
- There's no real standardization layout for laptops. And there shouldn't be, considering that it would severely limit how OEMs can design their laptops.
- The cooling system in laptops is often an everything-together solution, unlike the individual solution for desktops. Upgrading one or the other means having to work on the entire system. Imagine if you were to change your video card in your desktop, and every time you did that, you have to take out the processor heat sink.
- Speaking of cooling, the system in laptops is often designed to just cool the worst case scenario for the highest-end part in that configuration can handle. And if you want to cool something more powerful, well you have to get a beefier heat sink to do it. We could have different sockets/connectors for different power levels, but that's just a logistical and consumer nightmare. It's bad enough Intel has two consumer desktop sockets instead of one.
The point is, laptops, as small as they are now, cannot really be made with the same modularity as desktops, because modularity takes up space for all those connection interfaces, messes with the cooling, and considering that very few people who own a laptop have no desire to upgrade it aside from RAM (and we can throw in the excuse because there are no upgrade paths that there's no desire to upgrade...), there's no point in making a system that would be overall more expensive that only an insignificant percentage of the consumer base would actually use.
Well, I bid you luck installing that.