Pipersg
Why the hell should you have to use a passport for an internal flight on Ryanair when you don't on the national Flag Carrier.
Because it is in Ryanair's terms and conditions that you agree to when you make a contract with them (i.e. buy flights) and
The Flag Carrier's terms are different.
Airlines are businesses and they choose to operate in a way that suits their business model.
These business models are different to each other and this is reflected in the levels of service and the customer experience.
You have decided that you do not like this approach and will not use it anymore.
If a significant number of pax take your view and Ryanair's business is impacted, then they may change the model.
However, until then, what you see (in a t&c sense) is what you get, no matter how irritating!