Right off the bat, I realize that there are many Olynyk apologists out there and that he played with a hindering injury during the Atlanta series. He probably didn't have any business being out there with the shoulder injury, and he was more of a liability than anything else as a result.
I am dubious that his inconsistent offensive performance compensates for his lack of rebounding and defense. Yes, he improved his outside shooting this season and he helps space the floor. Having said that, there are too many instances where he is hesitant and doesn't make assertive decisions out there. He seems to lack the killer instinct required to take his game to the next level. He's too slow, too soft, and too meek. Is anyone convinced that his apparent redeeming features will prevail in the long run? Hindsight is 20/20, but I often imagine what it would be like to have the Greek Freak on this team instead of Olynyk. It's disappointing that we scouted him in Greece (http://www.sheridanhoops.com/2013/04/06/greek-freak-prospect-draws-danny-ainge-to-greece/) and then didn't pull the trigger.
This team needs a significant overhaul of the frontcourt in addition to more shooters in the backcourt. We have too many bigs who play below the rim and get stuffed down low and who cannot rebound effectively. I think Sullinger is a goner (too many outside shots to compensate for his weight issue which limits his mobility and ability to finish inside), and Al Horford had an underwhelming series and is another below-the-rim type player so I'm not sure he's worth a max contract at his age. Amir has his limitations, but I like what he brings to the table in terms of rim protection and tenacity. We need some luck on May 17th, I think we're due a top 2 pick.
Kelly had to play in the series against ATL. Sully got fat, Zeller was bad all year, we needed Kelly to survive the series even if he was not 100% ready.
Now, if you keep in mind that Kelly will probably never be a starter and lower your expectations, it's p clear he is a solid role player.
Looking at his number per 36 mins this regular season:
i/He is a below average yet not terrible rebounder (7.3)
ii/He has diminished the number of PFs which was concern in his first two seasons (down to 4.2 from 5.8 )
iii/Excellent 3p% (40.5) with almost double the 3PAs than in his first year (5.4 from 2.9)
iv/Below average yet not insignificant defensive presence (0.9 blocks; 1.3 steals)
v/Limited turnovers (1.9 from 2.7)
Now, having said this, his playoffs numbers were worryingly bad both this year and against the Cavs last year. Overall his performance when under under pressure is not great, he still needs to polish his game, but this should not distract attention from his real enough improvements this season.
http://www.basketball-reference.com/players/o/olynyke01.html