|You don't mind that I trashed the house, do you?|
Caring for others is intrinsically unpleasant. It's disgusting (exposure to all kinds of bodily fluids, nasty diseases and infections) and exhausting, because the work is endless (so you bathe, clothe, feed, amuse and rest the demented old person on Monday; on Tuesday you must do exactly the same thing all over again).
It's also very unsatisfying, because while it makes a tremendous difference, the effects are not easily measurable and tend to be long-term (meaning you don't see any obvious change/effect at the time). This is especially true when caring for the sick or old. While children will eventually be able to care for themselves, the best you can hope for with the chronically ill or aging is to slow the slide slightly. If you provide top-notch care to the guy with Alzheimer's, he will be happier and the course of his disease may slow, but he's still going to be demented: hardly a satisfying outcome for all your hard work.
Finally, people who need caretaking are usually not nice. People in pain are irritable, people with high needs are constantly demanding things, the elderly tend to be inflexible and stubborn. Leaving aside the undeniable cuteness of toddlers, their social skills and general pleasantness level generally leave a lot to be desired. Yesterday little R bit me in the face, just to see what would happen; she regularly has screaming fits whenever she doesn't get her way; and she has pooped on the floor (and on me) before. And this is a really delightful baby, as children go.
I absolutely believe that caring for others is extremely valuable; I would even go so far as to say that without doing it, you never become a fully developed human being. But the hypocrisy and self-delusion surrounding this act totally annoys me.
NB: Of course parenting and other caretaking activities aren't all bad. I do enjoy caring for little R a great deal, most of the time, and even caring for the demented has its moments of transcendence and reward. I am just focusing on the more negative/realistic side of things here.