we don't know how many 'able' people were travelling with the group
If you'd care to read the link you would know. Six blind, three partially sighted and three carers.
As much as I enjoy having a dig at ryanairs antics, I'd have to agree that they did nothing wrong.
Pax always go off on a rant about "not being given any information" when things go wrong with their flight, well it works both ways. Facts such as 9 blind or partially sighted pax should be offered when booking a flight, saying "no one asked" is not good enough. To simply answer "No" when asked if assistance is required is not good enough.
Unfortunate, but hopefully lessons have been learned.