They devote a a season to Barney and robin's wedding after setting it up for three seasons. Before they break it up in the first five minutes. They have Barney grow and evolve as a character to the point where he stops sleeping around, burns and later passes on the playbook, commit to quinn and then robin and then immediate have him start sleeping around twenty minutes into the finale with a playbook II ( why did they even film the scene of him handing the play book down to those two guys this season?) They have literally twenty episodes of ted giving up robin, to the point where he refuses to run away with her when given the chance in the previous episode and what do they do have ted and robin get back together and revert the mother to a plot device and baby making tool ( because remember robin doesn't want kids). Nine years of characterization pissed away in an hour they could have literally only made the pilot and this finale nothing else that happened matters in the least in the end,