In the London Review of Books, Paul Mitchinson investigates the damage that Leoš Janáček did to his career by his lack of tact (subscription required).

He persisted for years in misspelling (in multiple ways) Arnold Schoenberg’s name, and filled his copy of Schoenberg’s Harmonielehre with critical commentary. (‘Ass!’ he wrote in the margin next to a discussion of chord-construction on fourths.)

There seems to have been a little of this laying waste to normal human decorum even in Janáček's "most famous contribution to music: the 'speech melody.'"

In the summer of 1897, perhaps under Dvořák’s influence, Janáček began
notating the tempo and pitch of the conversation he heard around him:
the cries of children, the comments of neighbours, even the sounds of
farm animals. In 1903, as his daughter lay dying of rheumatic heart
disease, Janáček notated her strangled cries.