Does the Qur'an not allow Jews and Christians as friends?
Of course words can and do have exact definitions.
When a muslim woman marries, the Muslim bride must have a guardian (wali, in arabic), who is usually her father. But the same muslim woman cannot have a male friend (a non-mahram friend). So, if guardian and friend always had the same exact meaning, then you'd have a problem. Mahram refers to the extent of blood relationships within which one may not marry. Within these boundaries, members of the opposite sex may freely associated socially, without the restriction of things like hijab, veil etc. So, the father, is a mahram. Outside this, relationships are not allowed, eg Islam forbids boyfriends and girlfriends.
Many anti-Islamic article start by quoting one of the most common misstatements about the Quran: "Take not Jews and Christians for friends . . . ". If the writers of this had taken the time to study the arabic language they would have come to a better understanding. In arabic, the common word for friend is "siddiq". The Quran did not use that word in this verse. The word used is "wali" (see above for an example) which means protecting friend or guardian. The Quran is telling Muslims in this verse that they should not look to Jews and Christians to protect their interest in Islam. Why? Because Jews and Christians do not know or are sensitive to the special interest of Muslims that are unique to Islam. Would a Christian go to a Buddhist and say "Mr. Bhuddist here is my Bible I want you to be it's guardian and protect the special interest that the Bible has for Christians." No! That can only be done by a fellow Christian who shares that interest. There are too many verses in Quran exhorting the friendship between righteous Christians, Jews and people of other faiths with Muslims. Here are a few:
"Of the people of Moses there is a section who guide and do justice in the light of truth." (Qur'an 7:159)
"And there are, certainly, among the People of the Book, those who believe in God, in the revelation to you, and in the revelation to them, bowing in humility to God. They will not sell the Signs of God for a miserable gain! For them is a reward with their Lord, and God is swift in account." (Qur'an 3:199)
"Strongest among men in enmity to the believers wilt thou find the Jews and Pagans; and nearest among them in love to the believers wilt thou find those who say, "We are Christians": because amongst these are men devoted to learning and men who have renounced the world, and they are not arrogant." (Qur'an 5:82)
Regarding anti-Islamic, Islamophobic people, the extent of these people's hatred towards Islam, blinds them from using rational arugements and only increases them in their stupidity. For example, to quote one Islamophobe, IoshkaFutz, "As far as I'm concerned, this slipperiness of definition is the final touch of EVIL."
People who waste their time looking through these anti-Islamic sites won't find anything better than the rubbish vitriol rantings that come out of people like IoshkaFutz.
"Their intention is to extinguish Allah's Light with their mouths: But Allah will complete (the revelation of) His Light, even though the Unbelievers may detest (it). " - Qur'an 61:8