The issue is, are schools the best institutions for providing these (social) services? Even if schools could provide them, it still makes no sense to provide them through schools if other institutions could provide the same services better. Like, say, institutions whose core mission is to provide those services.
Even if we stipulate everything the unions might ask us to stipulate — that these services are needed, and that they can be provided effectively by a big new spending program, and that schools can provide them effectively — the idea that a bunch of non-educational services should be handed over to schools makes no sense. Unless, of course, the real goal is to build up the government school bureaucracy and its attendant gravy train — such as the unions who are making this proposal.
The really funny thing is, we’ve tried bringing social services into schools before. Fifty years ago, schools didn’t serve breakfast and provide teams of guidance counselors. Providing these and other social services in schools was originally justified on grounds that the kids needed these services to do well in school. How has that worked out?
I'll agree that our society has certainly changed, and that makes life extra hard on us educators. But that doesn't free us from the responsibility of teaching.