Triclosan is not only found in antibacterial soaps. It is also found in Colgate's regular and whitening toothpaste (this might be specific to Canada), where it comes into contact with your gastrointestinal tract.
Triclosan also has to be declared as an active ingredient in toothpaste, so it's not exactly hidden. Just spend 5 minutes reading some labels at the store.
Archeologically, before people started eating grains and processed "psuedo-food" we mostly died with good teeth and its a stereotypical observation that you can tell when grain agriculture sets in with a people when their teeth start rotting out at a young age.
Off the shelf at a regular store though, it's hard to find soaps (and toothpastes) without these ingredients. Just one more reason to DIY, especially with things that are going in/on your body.