Here's my take on Toine.
Toine as a rookie: most C's fans get hardons for young players oozing with talent and multi-skilled sets. Toine was supposed to be our "savior" or at least the primary piece to turn around our franchise.
Toine's early career: after the C's lost out on Tim Duncan, the Celtic fans turned on Toine, because Toine never lived up to the "hype that fans bestowed upon him". Toine was booed a lot at the then Fleet Center. The Pitino Era never once helped Toine but only hindered the fans' perception of Toine even more. Here was a young player too egotistical, to self interested, too stubborn and immature to listen to his college and now pro head coach.
Toine's prime: during the Jim O'Brien era, Toine helped change the culture of the Celtics (BEFORE KG ever changed the culture of the Celtics). Defense was the staple of the Celtics during this era, and Toine was not one who refused to play defense. Was he a good natural defender...no, but here was an instance where Toine worked hard to makeup for the physical tools he lacked. Under Obie, Toine shot some of the worst percentages from the Field in his career, yet the Celtics still won games and still went to the playoffs and still won playoff series.
Toine's twilight years: it is very difficult to assess when Toine's twilight years began, but I will say it started to rear its head the moment Don Nelson decided to play Toine at Center for the Dallas Mavericks. Since then, Toine has had a significant impact on any franchise (other than the Celtics part 2 in 2005). On the Heat, Toine was more or a less a role player (sorry Toine, I meant "basketball" player). On the T-Wolves, Toine was a part time player. On the Grizzlies, Toine never played.
Conclusion: Toine was a player that had a lot of varying skills, but never really perfected one. I think he worked hard at trying to perfect one or two (3 point shooting, pass), but because there were too many areas to focus on he couldn't succeed. As a Celtic fan, I had high hopes for Toine, and he lived up to them. No he didn't bring us a championship, but when he was booed mercilessness by Celtics fans, my hopes for Toine and respect for fellow Celtic fans diminished. I felt Toine was unfairly treated by certain Celtic fans and it spread to the national media, to Danny Ainge etc. I felt most happy for Toine when he found some sort of success during the O'Brien era. I feel most bad for Toine right now, that he didn't work extra hard to stay in the league. I believe he can still play. But I do not believe he realizes that a player has to work extra hard later in his career to stay in this league.