As far as having two kids goes---yeah, that's exactly the point of leet coding tests. If you don't have the time or energy to waste on mastering pointless exercises, you won't have time and energy to work 60-80 hour weeks. They want to filter out people with adult responsibilities, and adult problems.
Basically, are they going to hire one of you--experienced enough that you can recognize bullshit and so you will be continually pushing back--or two new college grads, single, no social life, and eager to do whatever it takes to make their mark on the world?
Alas, if you want a job coding at a company like facebook, google, bloomberg, etc etc you simply are going to have to be crackerjack at puzzle solving and leet-coding. Think of it more like hazing week at a college fraternity rather than as a test for how good of a coder you are.
Personally, I think it's ridiculous. If somebody has been programming since the Reagan administration at companies like Microsoft and AMD and Facebook, they will do fine wherever they are hired. But it is what it is.