Danny just is awful drafting bigs.
He has to trade to get the prize big , and thats impossible to compete with the LA teams for the best centers , they all,head for LA soon as their rookie contracts are up ....so either you have to be a great drafter of bigs or tank for the best center like Philly till you get one.
From the position we are picking there are rarely any surefire big man prospects. You always go BPA.
He's had 16 years to draft a great big man. I'm still waiting.
I'm not sure Romeo was BPA.
I'm not being sarcastic, but what great big men could he have drafted? Giannis comes to mind. That was a big miss, but in his defense, no one, not even Milwaukee, had any idea how good Giannis would be. What other big men did he miss on? I'm not talking just about guys who have come into the league, but guys the Celtics actually could have drafted at their spot.
A big one was Capela in 2014. Ainge drafted James Young at 17, around the range of where Capela was rumored to go, from the late 10s to late 20s. He ended up going 25th to the Rockets. Capela was athletic but raw and definitely a project. Also, even though we probably never would have drafted him, Nurkic went right before at pick 16.
In 2015, Ainge took Rozier at 16. There weren't really any good big men around that spot, but Kevon Looney was taken two picks after RJ Hunter at 30. Montrezl Harrell was also available, he went #32. Not world beaters, but solid guys nonetheless.
The 2016 draft didn't have a lot of great big men (that was the year of Bender, Chriss, Poetl, Maker, etc.). Sabonis did go 11th but we didn't have a pick there. The one that hurts is Toronto took Siakim at 27 and we took Zizic at 23.... =(
2017 was the Tatum draft. We weren't really in any position to take good big men that year, though it's too early to tell how a lot of those players will pan out.
In 2018 we took Rob Williams, which was a nice value at 27. Mentality/work ethic issues were likely the cause for his drop, so we'll see how he develops.
Anyway, I suspect that Ainge's philosophy is that if a big man isn't multifaceted there isn't much point in taking them, and he seems to prefer taking his shot at guards and wings. Since we're usually picking mid teens to twenties, you're just not going to find tall guys who also have other skills there. Anybody 6'10'' to 7'1'' who has a whiff of being a good passer, shooter, or playmaker IN ADDITION to normal big man skills is almost always snatched up early. That being said, there are exceptions in history: Jokic, Draymond, Jermaine O'Neal being the examples that come to mind.
Also, there was a point, maybe in the 90s and aughts where it didn't seem like the Celtics were as advanced with their European scouting as the savviest teams were.