I don't know, it makes sense to me. Spartacus' revolt was far from the only slave revolt in Ancient history, and a great deal of the over-taxed, under-fed and opressed masses that the poor sods under Roman control were indeed had to resort to briganding to be able to survive.

I wouldn't assume that it was all peace, quiet and prosperity in the Roman empire - especially in the Republican period. Far, far, far from it. The only people that really benefited substantially from Roman rule were the small elite in Rome...