There's a fascinating element in the discussion of the Sabbath year in Deuteronomy 15. The general law requires releasing people from their debts every seven years. That means if you lend to someone a few months before the release of debts, and the person is too poor to pay it back in time, you have to release them of the debt. You might expect this to give rise to unprecedented amounts of stinginess in the time before the year of debt-release. The law anticipates this, though, and it commands Israel not to use such fears as excuses not to give. It's sin to refuse to give in such a situation, and they were commanded to give and not grudgingly. It says God will reward those who get stiffed in such a situation.
In the debate between complementarianism and egalitarianism about gender distinctions in marriage, egalitarians often say that calling on a woman to submit to her husband is unfair when the man isn't called on to do the same. This does ignore that the same Ephesians 5 that tells women to submit to their husbands commands husbands to love their wives as self-sacrificially as the love that brought Christ to die for the church, which I think should count as at least as significant a level of sacrifice as what the wife is asked to do. But one thing complementarians often say strikes me as missing the point. They say that in any ideal marriage this shouldn't be an issue. If the husband is loving his wife as Christ loved the church and gave himself for her, then it won't be difficult at all for the wife to submit to the husband.
One hint that something is amiss here comes from considering the flip-side, which would be: If the wife submits to the husband, then it won't be difficult to love her as Christ loved the church. Really? I suspect it would still be immensely difficult for a sinful husband or wife to follow these commands even with a sinless spouse.
But I think the main reason I don't like that complementarian response is that you shouldn't have to go to the ideal situation to see that these commands are all right. If complementarianism is correct, then wives should submit to their husbands even if their husbands are complete jerks, and husbands should love their wives as Christ loved the church even if their wives are as unlovely as someone's inner self could be. Indeed, I would say this is so even with an egalitarian interpretation of this passage. This is simply Christian teaching. Philippians 2 makes this utterly clear. Christ's model of giving himself for us is just plain the model for Christians and how we should treat others, regardless of how those others treat us. And this is simply continuous with the Hebrew scriptures, including the Mosaic law, since the very same principle underlies the command in Deuteronomy 15 that lenders should give to the poor even when there's little chance of getting the money back before the debt-release year (and many other places in the Torah, Proverbs, prophets, etc. along these lines).
So, while I don't think the complementarian reply above is correct (i.e. saying that in an ideal situation it isn't all that bad to follow complementarianism), at the same time I think objections to complementarianism that involve any claim that it asks too much are, at the very least, contrary to the very spirit of Christ and his call on the church. There are those who will resist such an ethic. They will say that Nietzsche was right in his diagnosis of Christianity as a slave-morality. I'm willing to grant that to a point, as long as they recognize that they resist Christianity in doing so. What I will have little patience for is those who think they can maintain a Christian ethic while thinking any unfairness here is immoral.
It reminds me of a discussion I overheard between two atheist philosophers, both of whom had some Christian influence when they were younger. One was giving a certain argument against a certain conception of hell, saying that it would be unfair, and the other said that it won't make much sense to use an argument that assumes God is fair against the followers of Jesus, since Jesus described God in terms of an employer giving the same amount of pay to the laborers who only worked an hour as he gave to those who had been working all day. These were day-laborers who subsist on a day's wage to live for the day. The Torah even requires people to pay day-laborers every day for that very reason. Jesus says God is like the farmer who pays the day-laborers a full day's wage even if they don't earn it. There's nothing fair about that arrangement, and yet Jesus says it represents what God's character is like. It's not remotely fair to ask Israelites to give to their poor fellow Israelites who will almost certainly end up with no debt due to the closeness of the year of debt-release. But it's very clear that biblical morality requires doing exactly that sort of thing and much more.