Hmmmm, i do wonder if the tenants are simply 'playing the game', Recently a couple of friends had threats of their deposits/bond withheld due to 'cleaning required'. One case went to arbitration where the landlord was criticised for their behaviour and the 2nd, my friend said she would go to arbitration and the landlord backed down. In both cases the letting agencies had said that there was no problem with the properties ie they were clean, but the landlords pushed.
Back in our military days, ever speck of dust, scratch, chip was recorded as we moved as we knew we would be charged as we left - and our hearts sank if new carpets had just been fitted!.
There are excellent tenants & landlords, but there are also terrible tenants and awful landlords. It seems to be a lottery these days as to which you get.