You are looking at apples and oranges. Yes, people may buy into BLT or VGF for monorail access (loved our stay at VGF in March!), but you do know that they have been doing a lot of maintenance on them, and that frequently the monorails aren't running? What happens when they have to take the entire system down, possibly for months in the future to replace the concrete pilings and structures that go through the lake? It will happen some day, and it will be down for quite some time. There will be no point discount either. It is what it is. You deal with it and move on.
AKL's pitch is the animals, but they don't guarantee that you will see much. We spent a week there in a savannah view room, and it wasn't until day 4 that we even saw a giraffe. Did we sell our DVC membership? Of course not. Oh, and AKL is absolutely one of the best resorts on property by far. We love it there.
Comparing this to fireworks at PI (which completely closed several years ago) or EMH at the parks is a bit disingenuous. Those are not perks at the resort, and outside the control of the resort.
If they were OK with staying at a hotel on I-5 (I'll assume you meant I-4 or I-Drive), then they weren't good candidates for DVC in the first place. Again, due diligence. We get many discounts being DVC members as well, including darn good ones for APs and PAPs. They can go away tomorrow. Would we sell our membership because these discounts went away? No, because we understand that they are a perk, and can go away at any time. If you are buying into DVC for the perks, you are buying for the wrong reason. The perks are nice, but you buy in with the understanding that they aren't permanent, and can change at any time. That's just the way it is.