>why make Good and Law so close
Because D&D has, for a while now, had the implicit idea that Chaotic Evil is even worse and more evil than Lawful Evil, and that the pinnacle of Good is the always-Lawful Good Paladin. The evil CEO is still seen as less evil than the serial killer, for some reason, even if the former does more evil in the long run - similarly, the classic Chaotic Good idol of Robin Hood is also, well, a lawbreaking thief. He steals from the rich and gives to the needy, but he's not exactly that shining pinnacle of Good y'know?
The whole Law vs. Chaos thing also fell by the wayside at some point - probably because it's easier to relate to Good vs. Evil, since it's such a common theme in, well, everything else. Law vs. Chaos is a thing in Moorcock, Poul Andersen, Warhammer and... what? The wilderness has been conquered by this point in time, while pulp writers lived in a time where that was less true - Man vs. Wild is less of a theme these days, and Good vs. Evil is literally everywhere. Also, Law vs. Chaos in a modern sense is very much combined with Good vs. Evil - anarchy is Bad, society is Good.
Hence 4E has Good vs. Evil, replacing Neutral with Unaligned 'cause that covers a bit more ground, and putting in Lawful Good as the now-usual "extremely good" alignment and Chaotic Evil as the "extremely evil" alignment.
I don't fully agree - I'm more of a Law/Neutrality/Chaos man, myself - but I can totally see where they're coming from and why they designed it in the way they did.
Also, Chaotic Neutral presumably got the axe 'cause it's a shit alignment that nobody understood properly and Lawful Neutral was a casualty of Law vs. Chaos becoming irrelevant - it's either Unaligned or Evil now. Or, well, then. 5E went back to the traditional system, being the huge throwback system that it is.
What, and have them codify Black=Evil and White=Good even more?