That's the problem right there. The thing is, it isn't.
When the response to this disease includes a push towards changing peoples' habits to become healthier, which is a proven way to lessen the impact of this (and lots of other) disease, we can include this vaccine for people at risk who cannot make a lifestyle change, like people over 75.
As you correctly pointed out, the disease is here to stay. Why should I put some unproven experimental medicine in my body, when being healthy and getting the disease has the same nett effect?