I think there is a major disconnect in who the celtic fans think the Celtics needed vs what Olynyk brings to the table for the team.
Celtic fans: We want an athletic, defensive monster , that is different than "ugly body" Sully. We are tired of small ball and getting taken advantage of in the inside. Basically someone that is like KG or resembles his game
Problem: The draft , didn't present the celtics with much choices to what the celtic fans wanted and i'm sure danny wouldn't mind having. He did mention Adams was also highly considered, and when he was gone at 12, they wanted to secure Olynyk next. Some fans are devastated that Dieng was passed on instead bc he also fits the "description" of that athletic defensive presence. But if you think about it and analyzed his stats, you would see a guy who was not a huge part of the reason why Louisville was so good. He had some good games and some bad ones. Watching clips his 18 ft jumpers is impressive but on avg only took 1 or 2 in games. He just isn't all that good offensively. So while you can say his defense is a 8, his offense is like a 6. Vs Olynyk whose offense is a 10 and defense is a 6.5 (basically can hold the ground on the person he covers but can't save his teammates).
Using these metrics, Olynyk scores higher and will bring a unique adv with him into the nba. Dieng while good defensively is no Anthony Davis or Noel.
So what olynyk brings to the table: A guy that is really nothing like KG. But perhaps more like a Dino Radja but with more potential. Radja i remember was a fine celtic, until he got injured. He was a consistent scoring pf, smart, grabbed his share of rebounds, clogged the middle and played on a brutal celtics team from 94 to 96. At one pt he certainly was the celts best player and its too bad he didn't have a better supporting cast. Olynyk on the other hand even though is on a rebuilding squad , has lots of talent around him. He was the top player from Gonzaga last year and it will be interesting to see what else he can do being surrounded by even better talent.
So again, Danny got the best talent available, and certainly met one big need now the celts have which is lack of scoring. If Olynyk and Sully can't cut it defensively, than you have the choice to keep one guy or have one guy coming off the bench and make a trade or draft a "special" defensive player later. Rebuilding is never pleasent but i like the direction our young team is headed in.