It's a euphemism for sites that are not censored and still allow free speech. Matthew Prince used to support freedom of speech but he's abandoned that concept a while back.
By throwing up their hands and claiming that it's too hard to implement.
8ch is not running a highly sophisticated software stack. (Quite honestly, their code [1] is pretty terrible -- it's a bunch of frameworkless, hacked-together PHP.) Nothing about their setup is especially elaborate or unusual; at best, "we can't ban content" is an admission of their incompetence.
What does "lawless by design" mean?