I probably haven't been doing this longer than you (dunno, this is my 3rd season), but I would give them a break for the following reasons: Failure to regain weight to pre-breading level. Health issue (RI, mouth, etc). Or, decreasing production (each year the clutches have been getting worse, smaller, etc).
Apart from that, they should be good to go.

What they do in the wild, by the way, is completely irrelevent to what we should be doing with them in captivity. They are not wild animals, they are captive animals. Wild animals are full of parasites, and very few of them survive to ripe old ages. We want ours to live as long as possible, and be as productive as possible, so we don't treat them as harshly as mother nature.