In my opinion eating eggs is endorsing animal cruelty to the mother hen. The mother hens suffer greatly in factory farms even those labeled as organic, cage-free, and free range. By buying or eating the eggs you effectively rubber stamping "I approve of this action." By definition endorsing is to approve. To eat an egg is to approve of the animal cruelty involved in factory farms.
Finally, small farms are not cruelty free.
By eating eggs, consumers are supporting the chicken industry, which is infamous for cruelty to animals. Chickens on factory farms are shoved into spaces that are much to small for them to exist in such great numbers, and they are prone to injury and cruelty. Mothers are quickly separated from their live young, who are raised as meat chickens. Even "free-range" or "cage-free" eggs often come from chickens that have been given unnatural hormones, which are then eaten by the consumer.
But I'm willing to bet that the same people who would say it does also support abortion beyond the first trimester, beyond the point where the fetus can feel pain. If they call themselves humanitarian, you might wonder if it refers to their diet. Any guess as to which party they vote for?
Eating eggs is not endorsing animal cruelty, but it also depends on the eggs themselves. Factory settings can make it cruel to the hens, but free-range eggs resulting from organic feed would not be as bad. Even with organic products, it is hard to have cruelty-free diet in the United States and elsewhere.
An egg, while having had the ability to become a chicken at one point in time, should not be the subject of animal cruelty. Eggs found in super markets were laid by chickens who's jobs are to lay eggs. These eggs do not have "mothers" they are simply produced for commerce. It is not as if the eggs were plucked from wild grazing chickens. The egg is not even a "being" yet is simply material. You might as well have a jar of carbon and call it abortion.
Eating eggs is not the same thing as endorsing animal cruelty. Is eating fish the same thing as endorsing animal cruelty? While some of the conditions that chickens live under are disgusting and cruel, the act of eating an egg is not cruel in itself. Is wearing a leather belt the same thing as endorsing animal cruelty?