I remember how generous California welfare has always been. I grew up south of San Diego and one of my mother's major squawks was how a pregant Mexican woman could come up to San Diego for the day, go into labor, have the kid in the U.S., which means the kid is a U.S. citizen, and then collect welfare. I never saw anything supporting that; it was just my mother's rant, but I know welfare was easy to get if you wanted it.
As far as I know, disability is paid by the states, not the federal government, and doesn't apply to mat leave, which the employer pays for, not the government. I would guess that mat leave is handled somewhat differently from one state to another with some kind of federal guidelines. I've never heard anyone complain about getting lower pay due to mat leave or disability but some people complain no matter what. Sick leave is different from mat leave/family leave and when sick leave is used up, no matter what for, it's used up. I don't see how childed employees can use sick leave to make money any more than non-childed. Parents are absolutely not the only ones who abuse sick leave. Calling in sick when you're not is definitely not exclusively a parent thing.
And the variation among different company policies in re: childed versus non-childed is considerable. Where I work, people with children don't get anything special. Flex time is available to everyone, sick leave policy is equally applicable, mat leave is 8 weeks, there's family leave for other than maternity available to everyone, same sex partners can be included for insurances same as heterosexual couples. If a parent has to leave to tend a sick child, their work is left until they get back unless there's an emergency (in fact, I knew someone who was fired for taking his kid with a 103 temp to the hospital on Christmas Eve so things are not as cut and dried as they may seem). For some types of positions, people can elect to telecommute but that's not reserved for parents only. Frankly, I have never been asked to cover for a parent, I've never worked where someone could leave early for child related reasons without making up the time or being docked for it, nor have I ever been passed over for promotion or given lower pay or anything even remotely along those lines due to being CF. Again, I've found that there is a huge difference from one employer to another. I don't know if it's due to company size, type of industry, region or what.
The whole thing is that there are plenty of complaints on both sides of the fence but no factual information proving the validity of the complaints. Personal experience is limited so trading stories about this welfare cheat here or that benefit-abusing parent there doesn't really show the overall situation. I really don't care that parents get tax breaks for their kids. It's miniscule compared to what the wealthy individuals and corporations get. Since I don't pay for anyone's mat leave, I don't care about that, either, especially since mat leave is part of the Family Leave Act in which people have the right to take leave to care for elderly parents or an ill spouse. I'm not willing to lose the benefit that would be mine for non-maternal family leave so, in fairness, I can't get worked up about mat leave.
Again, one always hears one-sided complaints but no factual information proving one thing or another. The problem with all of these things is that I've never seen any unemotional comparison of the costs of having kids versus not having them, taxes, employment benefits, costs, everything included.