The notion stems from the emphasis Islam places on honoring the mother and giving the daughter a good upbringing, because they will be the future mothers of the nation. As one scholar pointed out, the mothers are the first and most important schools (sources of education) of the nation. Thus, we understand the Prophetic statement, Paradise lies under the feet of your mother (Musnad Ahmad, Sunan Ibn Majah, Sunan An-Nasaa'i) to be emphasizing that paradise comes from the serving and honoring our mothers, the women of the nation. Likewise, the Prophet Muhammad pbuh said Whoever cares for three daughters, gives them a good upbrining, marries them to good husbands and treats them with compassion, their reward will be paradise (Sunan Abi Dawud). And Whoever had a daughter and does not prefer his son over her, Allah will admit him to paradise because of her (Mustadarak Al-Haakim).
As for why the emphasis on hijab, it is an issue that many people have misconceptions about, and needs to be clarified. As for the plight of Muslims, this will change once Muslims return to their religion.
Peace.