Adam, you're right to point out that the process for joining a law faculty as a tenure-track junior professor is not family-friendly at all. But once you're hired, a law-teaching job is pretty much the model of a family-friendly job—the schedule is extremely flexible. Other than classes and some light committee work, individual faculty are pretty much in charge of when they come into the office and when they work from home and how much they work—at least in the short run.
True, tenure is typically up-or-out after a fixed number of years, and pay tends to be lockstep or close to it, but as I suggested vis-a-vis firms, that's not necessarily a bad thing overall. It prevents faculties from stringing junior faculty along and makes faculty life more equitable. And, in fact, the tenure rate at law schools (not university departments, just law schools) is quite high—I'd guess better than the rate at which associates are promoted to partnership at big firms. The tenure clock is also stopped for paternity leaves, and unlike firm practice, you can usually simply pick up where you left off with the type of research and writing most professors do.
This isn't because law schools are somehow more virtuous than firms. Rather, it's because what we do is different, because we aren't as immediately and directly disciplined by market forces and because we've all already decided to make the lifestyle-for-income tradeoff. As for options, one can join a law faculty as a clinical professor or teaching professor at many law schools with dramatically reduced expectations for scholarly output, and one can teach part-time as an adjunct professor.