Why it didn't happen already years and years ago?
Because its an additional cost. I really don't see the point, if 27% of pax are already business as claimed in the link. I certainly have used FR for business travel in the past.
FR is now well on the way to being just another airline; I suspect the changes have been forced through as MO'L is getting ready to leave the company, and his successors know they cannot emulate his business style. Time was when I could go to the Ryanair website, book a cheap ticket knowing that all the money was going to the airline, know that when I saw the aircraft arrive at the gate we would be on and pushing back in 25 minutes (or less on a good day), my flight would be on time and my baggage would get there at the same time as me - on one occasion at Edinburgh my bags arrived on the carousel 20 minutes before those of my colleague on the Aer Lingus at an adjacent gate, despite his plane landing 10 minutes before mine!)
Now, every transaction I make with FR will have a slice taken to subsidise the Amadeus fees (and discounts to retailers so they can get their commission). Allocated seating slows boarding - no need to rush now, you don't have to get to the aircraft to make sure you get the seat you want. If, as suggested here
Ryanair tie-up with Amadeus paves way for codeshare deals with national carriers | Business | The Guardian codeshares and long haul feeding start, they are going to start to get into issues of baggage transfer (and losses), delay payments for connecting passenger etc - more costs, more delays. So fares will go up, and FR will be no different to EI, BA or Lufty.
Of course, the middle-class, Daily Mail reading blue rinses will love it - the hoi poloi will be back to the boat and train to England and Europe where they belong, not cluttering up the genteel airports.