Its the correct decision but I still feel sorry for him.
What disappoints me, I think, is not that some people criticise him, that's fine - but that it seems to me that there's plenty of United fans who want to kick him when he's down and pour more misery on him.
We know the media love to shred our players but it really does feel like our fans have joined the pile-on at times. I have actually heard boos at times from the Stretford End when he warms up. I just cannot wrap my head around that personally. We've had some genuinely rank-bad players (Fred/Weghorst) that never got that treatment - and nor should they, just because we don't rate them.
He's become symbolic of our failure over the last three or four seasons, but he is far from solely to blame. The fee was always going to be an albatross around his neck but he was largely good for us, until we totally changed the way we wanted to play and forced him out of his comfort zone.
He's not a world class defender but he should go elsewhere, to a team that suits his style, and enjoy the rest of his career. I think people will be surprised how good he can be when/if he goes to a team like West Ham or Spurs.
Best for everybody if he moves on. It hasn't worked, sometimes he was very good, sometimes he was very bad...but I felt we (the fans) treated him quite poorly at times