No, the parent post makes a quite reasonable point that it can't exist, not because of any resource constraint but because there can't be a globally, universally acceptable appropriate moderation standard - different subcommunities have mutually incompatible requirements which can not be satisfied by any common standard; what's clearly acceptable in one place may even be illegal to say in another.

Well, perhaps you can, if you limit the discussion so that you can't discuss borders of countries, existence of certain countries, rights of certain groups, existence of certain groups, self-identity of many of your users, politicians, politics, religion and a bunch of other topics. If you ban all of these and permit just posting what you had for lunch, then perhaps you can make an universal moderation standard - but I would not call it "appropriate moderation" anymore.

That's a the normal, flaccid excuse. Twitter has the power to overcome the exact obstacles you mention. It's a choice to abstain from moderation, in favor of profit, like I said.