Why did some readers accuse James Boswell of vanity after The Journal of a Tour to the Hebrides was published?

After the 1785 publication of The Journal of a Tour to the Hebrides, some readers accused James Boswell of vanity and personal fatuity because he violated a conventional literary rule of the time: an author seeking respect should not document their own follies without simultaneously highlighting compensatory strengths of character.1

Boswell recorded his own weaknesses and vanity with the objective detachment of a historian. Furthermore, in his accounts of Samuel Johnson, Boswell ruthlessly subordinated his own personality, reporting instances where Johnson criticized or rebuked him without offering the reader reassurance that he understood the implications of those moments. By presenting his own flaws so candidly and failing to defend his own dignity, he invited the scornful perception that he was foolish, a reputation that persisted despite his clear intelligence.1