I was gonna disagree with the OP. But I changed my mind. I agree with OP.
OP is working; he should not be faulted for not being able to earn enough. And while the child subsidies were always a gift, I think they are being wrongfully taken away, because of the following:
Government tax and welfare policy is generally based on capacity and need, balanced by availability of social resources. A child subsidy is very good policy, since it targets need very accurately. Of course, it is balanced by the availability of social resources, as AviK points out.
But this was sold to the country as a way of getting at the chareidim and arabs, since they are the ones who have large families. This wasn’t done out of careful consideration of needs and resources–it was done out of not caring about the “other” (or really out of wanting to hurt the “other”).
The charge that chareidim are the parties who forced these subsidies actually proves the point. Society shouldn’t have to be forced to realize that large families have more need than small families with the same income.
Even if you think the chareidi kollel system is wrong or untenable, and that there shouldn’t be kollel payments or army exemptions, that really shouldn’t affect how you think about child subsidies.