I think the relationship reflects us, the audience and our attitudes, prejudices, stereotypes and ideas more than anything.
We're all conditioned to see the hard nosed Asian Dragon lady wife.
We're also conditioned to see the stereotypical Irishman who continually tries to do good but good seldom happens to him.
The relationship of the two just reinforce all our ingrained attitudes about all that ... and often, that is all we see or want to see.
The difficulty arises when we are forced or force ourselves to see them both in a different way. It makes us uncomfortable because it makes us wonder if there is nothing wrong with the characters but maybe there is something wrong with us and how we see them. We .... and that includes me ... find it easier to see something wrong with the world, rather in considering there may be something wrong with us.
I'm watching DS9 from beginning to end right now and the more I watch, the more it makes me think about the world and how I see it .... and I think that was one of the biggest impacts that this couple was trying to gain from the audience.
Thoroughly loving DS9 and I just love jumping in here to talk to you all about it.