First off.
I never said keep them, that decisions is down to the individual.
As for form ratings.
How many times do you see a player score two goals and maybe an assist or two get a 7 and then someone in the team who did very little get a 8/9 with the MOM, that is what I mean about random.
I know how you are feeling I have several scout players who cannot gain a skill point for love or money, but The game engines tricks sometimes have to be ignored when it come to team selections and players being sold.