Dak
mentat
There needs to be the consideration that the "nuclear family" shouldn't be the privileged form of household organization. Sowell assumes that the nuclear family is some sort of secret formula that ensures survival or success. The racist assumption being made, even on Sowell's part (and remember, racism in this instance need not be intentional or individual, but is instead cultural and collective), is that the Euro-American nuclear-familial institution is the best form of household organization and that blacks should conform to it.
During what portion of history were blacks most in accordance with this household model? Well, during Reconstruction of course, and the decades that followed!
Thus, if slavery provided blacks with the discipline necessary to form nuclear families, and history shows that immediately afterwards they all went out and got married, well then... eureka! It must be that slavery actually did something good for them. Bear in mind, no one is saying this out loud; but it's the implicit assumption as it derives from the other assumption: i.e. that the nuclear family is the privileged institution that should be pursued.
This is how racism works; it's complicated, it's multi-layered.
You're making a couple of unsubstantiated leaps here. It is not stated nor are there any phrases of implication amongst these (not to say it isn't possible they exist within their entire works, but I haven't seen them) works of Sowell or Williams that slavery did anything good. However, this sort of critique is problematic anyway, since slavery in itself is not homogeneous, nor is/was it homogeneous within the US, and we can that some sorts of slavery were/are worse than others - based on judging individual aspects separately from the whole - which in no way justifies the whole absolutely. If forced: would you have rather been at oars in a Roman galley or a house servant in the Deep South? How about a field hand in the Deep South vs a house servant um, mostly anywhere? How about a feudal peasant vs a US Taxpayer? None of these options are good, but some are better than others.
Now, there is significant correlation within at least the western paradigm of nuclear households and positive outcomes. Whether this is simply culturally contingent or not is rather irrelevant in a practical sense. Sure, one could see positive outcomes without the benefit of the nuclear household even in the west, but it becomes less likely. Maybe the some other structure would render different results in a different system, but we aren't in a different system. The world, for the most part, isn't in a different system. So: a systemic assault on a [racially] based grouping regarding factors significantly correlated with success within the system (rather than trying to change the system) is quite easily chargeable with being racist. On the other hand, saying that the system is racist for encouraging success and being open to integration acts as defense tactic for the former, regardless of intent. It might make the speaker feel good to talk of complications and layers, but it doesn't even remotely begin to help the kid in the projects like a positive father role model would. Of course, the people speaking of complications and layers grew up primarily in nuclear households - generally ensuring their successful positions from which to be concerned with the misty arguable abstracts of layers and complications rather than who loves them and what they are going to eat tomorrow. This isn't aimed at you or your defense specifically, these are the stat-ist-ics.
Of course, there are other household structures that might work (Mormons have seen success with polygamy, and some agricultural cultures have seen success with polyandry), but single parents (mostly moms) living on state handouts has not been a recipe for success anywhere - and that is what has been pushed as the alternative by the above. The nuclear family is certainly privileged vs The United States Substitute Daddy System or x_street_gang. Which is all the Coates of the world have to offer.
EDIT: new Aeon piece isn't saying anything I haven't already thought aboutcool
but... it's still a mighty fun read:
http://aeon.co/magazine/world-views/logic-of-buddhist-philosophy/
Yes this was an interesting read. Needs re-reading.