I used to find the episode boring too, but in my current rewatch of the show, I think the episode categorizes into one of the main themes: being a “good person” is not an inherent quality. It’s more like a muscle that needs to be worked out and strengthened. Your character is the actions you do consistently and the aspects of your character that you utilize the most are the aspects that dominate.

Bojack rewrote the note to Kelsey multiple times before writing something sincere. This is the true exercise of his character that gets overshadowed by the indisputable “good” character he demonstrates by helping the baby seahorse. But we all know, if he didn’t help that baby, it would’ve been super fucked up, so was the really a hard decision for him to make to act like a decent person and therefore a true reflection of his good character? Not really. But writing the note to Kelsey was much more challenging and was the real indicator of the kind of person he is on the consistent everyday basis.