In fairness, the default reply settings include a full quote which is unnecessary but obviously not the fault of the poster. When a thread is tidied up it is done so at specific periods when a reader can follow the thread without much contextual difficulty that might not have been apparent when the post was first made. There are a few posters who engage in “windbaggery” or puffery and nonsense that seems important to them but nobody else. Emboldening every other word for no particular purpose, multiple but unnecessary punctuation marks, stretching a post by misplacing a period mark 20 lines down, and more besides. Tidying up is intended to keep a thread readable and inviting to the majority rather than a select clique.
Same with profanity or personalisation nonsense. It simply tends to escalate as each successive and incensed poster feels the need to outdo their predecessor. The intention is to keep a thread alive, dynamic and inclusive rather than resulting in deletions and thread closures.
The quotation boxes are useful where they refer to a significantly out of sequence or old post. Similarly, where it seems necessary to follow the thread, more so when it is a specific excerpt rather than a complete repeat.