I think the point is at the time that Scheierman was drafted, what was the immediate need? Plenty of people were saying that BOS needed another shooter. A prospect big to replace Horford some time in the future was not the priority. Now it turned out that Scheierman did not help the team. Scheierman has not even lived up to the limited expectation of a 30th pick. But was the philosophy of picking a player you hoped could help now the wrong philosophy? The player you hoped was more NBA ready?
I really think it can be a wrong philosophy, if you don't take into account basic athletic ability. Guys have succeeded with all levels of athletic ability in the NBA. I think wings and guards are generally speaking the most athletic guys. Picking a guy who doesn't have foot speed at these positions is not good judgment. You can't get open, you can stay in front of your man and etc., etc.
The amount of importance this franchise has given to bigs in the post Bird Era is very low and has always been disappointing. Ainge got KG and he was the last great big we have had. Al was a good big and more than serviceable. Neemias shows promise. But how many times do we have to get destroyed by other teams with size, before someone realizes it?
You need to have some rim protecting and rebounding to play any style of basketball effectively.