I think this might also have something to do with trying to make as much money as possible other than from charging pax fares.
The more revenue they can generate from other sources, the easier it is for the airline to maintain low airfares, and thus maintain loyalty from the punters.
You as pilots may find the practise disgusting, but it actually makes good business sense.
And despite many saying they won't now apply to Ryanair/fly Ryanair, the fact is there are many more that will, for many reasons, and the charges won't put them off.
That's the reality.
Regards