"Unacceptable" and "medieval" mean what exactly?

Seven men in Oxford have been convicted of involvement with a paedophile gang.  Their names are Mohammed Karrar, Akhtar Dogar, Anjum Dogar, Bassam Karrar, Kamar Jamil, Assad Hussain, and Zeeshan Ahmed. Could they possibly be Muslims?

The Daily Mirror reports:

Jon Brown, of the NSPCC children's charity, said: "The girls were let down by those who were meant to care for them and obvious signs of abuse were missed. Their treatment was unacceptable."

The Daily Mail reports:

Jon Brown, of the NSPCC, said: ‘The Oxford grooming trial has been a grim reminder that even though we are living in the 21st century some people have retained medieval attitudes towards young girls.’

What does unacceptable mean?  Does it mean that the politicians who for years ignored the problem of Muslim paedophile gange should be punished?

Also what does medieval mean?  Islam is a medieval religion.  It was cobbled together at the end of the seventh century.  The Koran promises sex slaves in the hereafter for Muslim men, and says that Muslim men are allowed to have up to four wives, and are allowed to beat and rape their wives.  They are allowed sex with any woman they can possess with their right arms.

Update: the council chief executive and the chief of police are both refusing to resign over this scandal.