The difficulty is that in many cases it's the local authorities who are the ones spreading the inflammatory content and their requests for moderation are actually requests for censorship.
By that logic, shouldn’t any company whose services could be politically consequential get out? Then doesn’t that deny the population the tools they could use to influence their country?
They should stay in the market only if they're willing to put in the effort to make sure their political effects are neutral or positive. Facebook clearly isn't willing to do that.
That may be the case for Burma, but in this case the government was trying to halt said inflammatory content.
Facebook policy, however, doesn't care about the differences; it just wants to do whatever requires the least effort while maintaining high market share.