Most of those brands are owned by larger companies now. Tom's is primarily owned by Comgate-Palmolive. Jason is part of Hain-Celestial.

I doubt it's financially feasible to advertise on TV for the sales they expect in their niche. I'm not sure if it's the best way to reach people interested in natural toothpaste. I don't know whether consumers would think they stand out for not advertising, but it's possible that some customers prefer a a less known brand for some sort of feeling of exclusivity.