Because we were actually 5th in the playoffs in number of drives to the basket:
(click to enlarge)

I am surprised they were 5th in drives.
So 5th in overall drives but that drops to 9th (out of 16 teams) in FGA. Comfortably middle pack. So an average team on shooting off of drives. That makes more sense. Looks like there are a few outlier teams at the top who did very well in the first round and then everyone else clumped together. LAL finished bottom trailing the rest.
Then BOS drop to 15th out of 16 teams in FTA off of drives. Only LAL got to the FT line less off their drives and they had less drives than anyone else in the league.
BOS 4th in passes off drives. OKC, POR and TOR ahead of them. Houston behind BOS. I'd love to know how many 3s BOS took out of passes off drives but the page doesn't show that info.
8th in turnovers off drives. Middle of the pack.
Personal fouls? I presume that is fouls drawn rather than offensive fouls. BOS 2nd lowest with 3.0. Only LAL is worse. Makes sense given the two teams were bottom for FTAs.
Hmm ... interesting.
Yes I was surprised too. Also as you say they weren't very successful at it, and they didn't draw the fouls that you could expect a team 5th in drives to do. I might see if I can break that down to Games 1-4 and then Games 5-7 to see if there is a meaningful change.
Imagine a world where the 76ers actually game-planned against the Celtics to take away the best shot available (shots at the rim), and imagine a world where every team in the NBA does this, because the C's philosophy (which is a league-wide philosophy) is to look for the best shot.
Now imagine a world where the C's are loaded with average-to-above-average 3-point shooters, are near the top of the league in taking wide-open threes,
and are playing a team that is trying to keep them from driving to the rim.
Now, if you can stack another layer on top, imagine telling these good-to-great 3-point shooters to pass up on wide open threes because the vibes aren't right.
That is the state of the conversation around shot selection right now. People should be mad that Brown was auditioning for a career in masonry during Game 7, not that Boston was taking good shots.