The point about this is that the travelators and escalators at Manchester seem to out of service more frequently than those in other airports, stations, shopping centres, etc, and not that this does not happen elsewhere. Having lived in HKG, where there are escalators everywhere, other than for planned maintenance, it was rare to see one out of action for more than 24 hours, and not weeks as at MAN.
I cannot recall a single occasion in recent years when all the travelators from T1 to T2 have been working when I have passed through the airport, and more often that not at least one has been out of use. Maybe, I am unlucky and don't travel through MAN frequently enough to see them all working, but from the comments of others, I suspect my observations are correct.