Answer

I agree with @nsn's comment - also, Ryanair's approach now is to encourage all passengers to use online check-in.

From Ryanair's check-in policy today:

6.2 All passengers are required to check-in online via https://www.ryanair.com/ and print or download a boarding pass except Business Plus fares which include free airport check-in.

Context

For context, see this Telegraph article from 2009 describing the change to their current online-only policy:

Do I have to check-in online?

From May 1, all new bookings will be required to use online check in, while Ryanair will begin phasing out check-in desks during the summer. Passengers who book tickets before May 1 will still be able to check in at the airport, but from March 19 the fee for airport check in will be doubled to £20 per person per flight, in an effort to persuade passengers to embrace the new system.

Also, the same article (remember, written in 2009) notes the policy change impacted non-EU citizens:

I’m not an EU citizen – can I fly with Ryanair?

Ryanair currently does not allow non-EU citizens and customers with reduced mobility to check-in online. From March 19, the service will be extended to these passengers.