I think Amare was discouraged to comeback at his current status especially with a team that has played too well together. He made a comeback but it didnt last long, and it actually lead him to another surgery.
As a GM, coach, owner, fan you guys should understand that Amare is a decaded long plan. I think the team and organization is so confident that the Sun's window is still wide open. If this was it, they would of taken a risk and played Amare there... but even if Amare was cleared... why would D'Antoni risk the team's chemistry. Inserting Amare is not like inserting any perimeter shooter... Amare is effective when the offense goes through him.... you cannot change the gameplan that got the Suns into the playoffs and into Game 6 of the WCF just to put Amare out there.
I think Amare will not be 100% when he comes back next season. He will round off to his 100% maybe late in the season and definitely the season after next barring anymore injuries. He will be 80-90% when he comes back, sure he'd have a more potent jumpshot and a few more post moves... but the quickness, strength and explosiveness will not be near his peak.. but eventually, hopefully, the knee holds up as he re-develop the strength and explosiveness as next season progresses.