As far as "losing is fun" achievements go, I get the motivation for them, but I still think these should be very limited; 1 for adventure mode, 1 for fortress mode, and maybe a couple of "fun" ones that may also qualify as challenges (for example, lose a fort within a day of embarking), and maybe another couple to do with reclaiming a fortress that was retired or ruined. Maybe also one for losing a certain number of forts (not from specific causes, just *a specific number of them*, and no more than 10).
But beyond that, I agree with the arguments made about avoiding having a "checklist" of ways to lose, and I don't think making them hidden is a good answer to this.
Achievements should by and large fall into the categories of "diverse gameplay" achievements (ie encouraging trying out mechanics), "first time" achievements which are the likes of your first werebeast, first discovery of candy, first siege etc (ie things that "happen" to you while playing, not things you accomplish), and "challenge" achievements, like starting an embark and living for several years without harming any trees or using non grown wood, or that "vegan fortress" someone mentioned above, or having a dwarf born in the fort die of old age.