I don't think that believing that the Quran is a direct revelation from God makes social reform difficult in Islamic society.
I actually believe that if Muslims in majority Muslim countries would actually apply Islam correctly they would function better as a society.
It's true that sharia influences the legal codes in most Muslim majority countries, but those legal codes have been shaped by a lot of things, including, European colonialism. France, and England and others imposed nation-state models on nearly every Muslim-majority land.
Majority of muslim societies are in need of social and political reform, because their governments are corrupt, they don't meet the needs of their citizens.
The practices that you mentioned such as polygamy, inheritance laws,'beating the wife' all fall under the Shariah. The problem here is thay the majority of non muslims have no idea how Islamic Shariah works.
Sharia is not a book of statutes or judicial precedent imposed by a government, and it’s not a set of regulations adjudicated in court.
It's a body of Quran based guidance that points Muslims toward living an Islamic life.
It doesn’t come from the state,it doesn’t come in one book or a single collection of rules. Sharia is divine and philosophical,it's a framework.
The human interpretation of sharia is called fiqh, linguistically it means understanding
Fiqh is the product of application of usulu fiqh, the total product of human efforts( Islamic jurisprudence scholars) at understanding the divine will.
It deals with the observance of rituals, morals and social legislation in Islam such as those you've mentioned.There are different schools of thought and different interpretations how the verses and hadiths should be applied. So we don't just take a verse and apply it literally, there's a process.
Does this process make it permissible for Muslim men to engage in polygamy and beating ones wife? Let's ignore secular sources of law for the moment and let's discuss Islamic law and what is allowed in it.
If you say these are not allowed, could explain how one can come to that conclusion?
Quotes from Quran from Surah of Women
If you fear that you will not deal fairly with orphan girls,c you may marry
whichever [other]women seem good to you, two, three, or four. If
you fear that you cannot be equitable [to them], then marry only one,
or your slave(s): that is more likely to make you avoid bias.
do.
129You will never be able to treat your wives with equal fair-
ness, however much you may desire to do so, but do not ignore one
wife altogether, leaving her suspended [between marriage and
divorce]. If you make amends and remain conscious of God, He is
most forgiving and merciful, 130but if husband and wife do separate,
God will provide for each out of His plenty: He is inf i nite in plenty,
and all wise. 131Everything in the heavens and the earth belongs
to God.
34Husbands should take good care of their wives, with[the boun-
ties] God has given to some more than others and with what they
spend out of their own money. Righteous wives are devout and guard
what God would have them guard in their husbands’ absence. If you
fear high-handedness from your wives, remind them [of the teach-
ings of God], then ignore them when you go to bed, then hit them.
If they obey you, you have no right to act against them: God is
most high and great. 35If you [believers] fear that a couple may break
up, appoint one arbiter from his family and one from hers. Then,
if the couple want to put things right, God will bring about a
reconciliation between them: He is all knowing, all aware.