Are All Cultures Equal?

Are all cultures on the same moral level? Are they all the same?

We commonly hear from the multiculturalist that we shouldn't "judge" other cultures and that we should be "tolerant" of them. If all cultures are equal, then isn't it arrogant to say that one culture is better than another? If we say something is wrong with another culture, is that because we just don't understand it?

How far should we take this line of reasoning? Are there any things that are just wrong about a culture and should be rejected? On what basis should we make a moral assessment of our own or another culture?

Is part of our problem today that some people don't make any moral judgments at all? Are there any things that are worth dying for? What about efforts at making moral reforms (e.g., like abolishing slavery or apartheid)? Is this a waste of time since all cultures are equal?