Just a quickie on this as I absolutely agree with you! We were on an EasyJet flight at the start of this year and as we walked on virtually the whole of one side had one person sitting in aisle and another by the window with the middle seat free. As I walked past the attendant half way down, I couldnt resist saying in a rather loud voice,"How strange that there are so many single people on this flight, and how lucky that half of them want to sit in the aisle and half by the window!" She just looked at me, smiled and half shrugged. The following flight, surprisingly, they actually mentioned that all couples should seat themselves to enable the aisle seat to be free.
And did they......???