“Modern usage has loosened up”
I'll say! Grammar lessons from the Comma Queen in the Rockaways:
p.s., unrelated: The Comma Queen (Mary Norris) tells a story in her book Between You and Me about writing a letter to James Salter (my James Salter!) querying four suspicious comma instances in Light Years (my Light Years!), to which he responded:
"I sometimes ignore the rules about commas although generally I follow convention and adhere to the advice in Strunk and White. Punctuation is for clarity and also emphasis, but I also feel that, if the writing warrants it, punctuation can contribute to the music and rhythm of the sentences. You don't get permission for this, of course; you take the liberty."