I do not use Macs, so I am wondering why or how a person would risk losing their images. Surly they are stored either on a hard drive, or online somewhere (always risky).
In either event, a person should have a backup, since no storage is all that reliable.
It is a bit puzzling as to why Apple would eliminate a highly regarded piece of software, at the very least, they might sell it to another software developer. The only reason that comes to mind is that Apple sees jpeg images from iphones, tablets, etc as the way forward. Its certainly true that camera sales are dropping like a rock.
Nobody would loose any images, they are all stored in a 'library' folder. You can view the contents and all your master images are in there, but i'm not denying it would be a total nightmare switching to something else without some software to automate the process.
I agree, it is puzzling to why they are stopping development for it? I mean in the grand scheme of things, they probably don't even notice the development costs and it's always smart to keep your options open right? You raise an interesting point about how they see jpegs/iphone images as the future, this is quite possible. Hopefully the new software will support RAW, otherwise i'm not sure what to do.