Well, there shouldn't be too much R&D an tooling to keep the 17 updated. All it really needed was USB 3, and the typical speed bumps they get. However, I can see how it may have made sense if sales weren't there. I don't really know the numbers, so I can only speculate. But they sold it for 10 years. I have a hard time believed it declined
that much.
That said, the 17 is what I consider to be Apple's best. It has it all, power, portability, expandability, and flexibility. There is
still nothing like it on the market. It really is unique, which is probably why used ones can fetch up to $3,000 out there.
Now, as to why the 17 vs the new, well, everything:
1. The screen. I'm sorry, but a smaller yet sharp screen is not a substitute. The difference is obvious and apparent. My last visit to the Apple Store for repair confirmed it. EVERYONE that walked past my 17 when sitting next to the other MBPs was like: "Whoa!" or "Wow!" or "That screen is
huge!"
2. Massive storage. Why 3TB inside? For the same reason they sell drives that big and put them in other models like the iMac. And the same reason why a 16GB iPhone is ridiculous. Some people need the space. I for one backup an iMac with my MBP. 15 Years of apps, photos, videos, music, and documents for a family of 6 take up A LOT of space. I simply cannot replace my 17 with, well,
anything out there.
3. Expandability & flexibility. The Expresscard slot gives me access to devices and ports that the others can't, and it's built in. I don't have to carry dongles of
any kind. Grab and go and I have everything I could possibly need. The ability to swap drives at will gives my computer longevity, as I can select different RAID modes based on my preferences (and available capacity).
So, to me it seems like Apple is lately targeting the young, single, self-centered hipster professional that has not accumulated enough "life experience", to whom everything is disposable, and trends matter more than substance.
A MBAir or MBP are very much single-user devices, like the iPad is. The 17 is a
desktop replacement. Not for everybody, but irreplaceable for those who appreciate it attributes. Like me.