Too many idle people is never a Good Thing(tm). It breeds insurrections, conspiracy theories, and the kind that go postal against random people.
As a baseline, consider the bombings from the 1910s (The 1910 Los Angeles Times bombing up to the Wall Street bombing in 1920.). I can't think of anything comparable during the 1930s and https://en.wikipedia.org/wiki/Timeline_of_terrorist_attacks_... lists nothing.
Work is only one way of not being idle. If it were, we would expect retired people to be insurrectionists, conspiracy theorists, and instigators of random attacks.
Students and stay-at-home parents also busy, while not being idle, nor being included in this definition of "labor force".