Bird outplayed Maxwell by a large amount that series but for whatever reasons(s) voters decided to rob him of MVP.
Just a few stats.
Bird 13 more steals for the series. (14 to 1) Steals are one of the best predictor of who wins...unfortunately the Warriors got a lot more steals than the Celtics last series and literally that may have been why Boston lost the series
Bird 25 more assists for the series than Maxwell.
Bird 35 more rebounds for the series which is a lot in a 6 game series.
Both Bird and Maxwell had 19 turnovers so Maxwell had a relatively speaking large amount of turnovers for getting a lot less assists and only a few more points than Bird.
Bird had much more gravity than Maxwell that series and obviously for his career. Not gravity compared to today's tremendously spaced era but he was still the one taking a fair share out outside shots including a few 3's.
Many people even in their early 50's have this misconception of Bird's early years since they watched him a lot less on television or just don't remember. Bird his first two years in the league led the entire NBA in defensive win shares and he led the entire league 2 more times in that stat. Bird in 81 wasn't a super efficient scorer for that era compared to his MVP years but he was still finishing 2nd in the MVP based upon his all around play which including great defense. But it was really his passing that stood out the most on offense.
Regular season MVP Moses Malone only shot 40% that series and Bird and then Parish were the Celtics best defenders on that team. Maxwell/McHale/Robey for sure chipped in with the frontcourt defense.
Boston averaged a little over 96 points per game that series and Houston under 87. Houston normally scored 108 points per game during regular season so the Celtics really slowed down their attack and where slowed by Houston as well. The Celtics improved from 19th defensively to 4th the year that Bird was a rookie and playing without Parish and McHale on the team yet. Bird was never a shutdown man defender but he was a good one in those early years and a great help/team defender. And often help/team defense is just more important than individual defense since picks can be set. He knew which chances to take and not take and hustled back after taking an unsuccessful chance. Bird's relative lack of speed wasn't that big of a deal in early years since so few players were taking corner 3's, his quickness was a big edge on d.
Bird has certain had even before he got old and injured bad playoff series but he was a superstar in that series so it really is disgrace that someone posted a tweet who probably never watched the games or just has zero understanding of what wins/loses basketball games.