it makes the story better for me in that i feel tremendous empathy with the situation. i get sad about how his mom is giving up her life to be bo's savior (and doesn't get a ton of credit) and also how bo can't constructively learn how to be an active player in his own life and stop resenting others. i think you're right, bleu_tropix, something bad definitely happened in the past, possibly abuse-related.
bo observations:
strained relationship with mother; mother is supposed to pick out suitable women and career for him, and without mother, he'd be "lost"
to some extent, he resents mother's control; frequently snaps at her in conversation in a frightful, irritated sort of way, leaves when mother and girlfriend start to get along
agitated reaction to the mention of deceased father...
bo had a chance to make a big name for himself in baseball and didn't...
had an awkward, terrified, and humiliated reaction to being recognized on a jog
he has a pronounced role as a "spectator," who watches others live: watches kids practice ball, collects news clippings for tyler, does not participate in sex [comfortably] and prefers to watch [but not to be watched]
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speculation: mom had to save bo from something
really bad once (possibly involving his father or father's death, kids in school, or possibly even the coach) and two things happened: mother coped with loss of bad husband by overparenting bo, and bo lost nearly all sense of efficacy. he starts to grow up and gain a sense of mastery again, which leads to struggle with mom, who continually asserts herself as a confident savior figure.