The quote of ibn Tamiyyah is on page 12 of book posted in above link
It says
“It is obvious that the [affairs 01′ the] people cannot be in asound state except with rulers, and even if somebody from among unjust kings becomes ruler, this would be better than there being none. As it is said: ‘Sixty years with an unjust ruler are better than one night without a ruler‘. And it is related of [the fourth Caliph] ‘All, May God Be Satisfied With Hirn, to have said that: ‘The people have no option but to have a rulership [imärah], whether pious or sin1’ul’. People asked hirn: ‘We understand the pious, but why bother for the sinful?’ He said: ‘[Because,] thanks to it, highways are kept secure, canonical penalties are applied, holy war is fought against the enemy, and spoils are collected”
Apparently, he mean that a ruler is needed to mantain law and order otherwise chaos will breakout in society.