My vague understanding with the A320 is that you are correct about the age and in a sense about the operators. It has only been owned however, by a few companies who controlled all the maintenance etc and then wet leased it to the others you mentioned. I can see how all those operators etc can seemingly put a tarnish on an aircraft's history
I wouldnt bother about posting that here, its been documented before but these 'armchair' experts with a can of
VB in hand obviously don't know how to read into these things.