I mean, this was probably my biggest fear about parenthood. Observing other parents, I've noticed that a lot of them lost everything that made them interesting. The kids are the only things they care about now. I don't see this as a good thing - not for parents, and not for the children. If a parent's entire self gets consumed by child-rearing, what example do they set for their children? That the point of their adult life is to have a (arbitrary, but hopefully well-paying) job in order to support their own children, perpetuating the cycle of doing nothing but breeding and dying? Isn't that meaningless and boring? To me, it is. And I'd hazard a guess that this is where midlife crisis comes from - when one's children are self-sufficient and the role of a parent is over, one realizes they have a 20 years old hole in their life, into which everything they were disappeared.

(This is my perspective as of right now. But the funny thing with perspectives is that they depend on where you stand - so who knows, maybe I'm wrong now and three years from now I'll be arguing the exact opposite? I don't expect to, but I can't rule it out.)