In Islam, 4 marriages are permitted as a practical solution to social issues like the welfare of widows and orphans, under strict conditions of justice and equity among wives, not as a normative practice for all men.
LOL, you would justify anything and everything in the name of Islam. You were once justifying how it's okay for women to be lashed publicly than them having to spend years in jail.
Polygamy is necessary for the society. Islam would have been wrong if it made it compulsory but that is not the case. In real life there are situations where polygamy can be solution.