What has really ruined my trust for Boeing is not necessarily the incidents with the 737 MAX model specifically, but more the change in that company's culture that these incidents have made me aware of. I can recommend this video[1], but the short of it seems to be that Boeing over a period of decades has replaced its previous "engineering first" culture with what I can only describe, for lack of better wording, as the "suits taking over", with predictable results.

[1]: https://www.youtube.com/watch?v=y_zn_x2JK5Q