What about people like my old grandmother? She cannot operate a cash machine never mind use an 'automated check-in kiosk', she does however use BA domestic routes on a semi regular basis and can cope with the 'normal' check in process with the help from the staff that this entails.
BA will have staff there to assist people in using them, so I don't think it should be a huge issue. Plus, if worst comes to worst, there will still be one or two desks open.