Most likely because it's not beneficial, as they'll be killed immediately if they reveal themselves, or executed if they don't die after the reveal.
All Toxes who won't be killed by the mafia). So you're right, let them reveal themselves.
Any Tox who reveals himself will be exposed to the real Tox.
I think the real Tox will immediately raise a fuss, and when he's killed, the "imposter" will be exposed. So the townspeople might not want to abuse this opportunity.

В тихой однообразной жизни всегда так бывает: каждый отдельный день бесконечно долог, но месяцы и годы мчатся с непостижимой быстротой.
I wanted to offer you some flowers, but a crown would suit a princess like you much better
Смысл жизни в том, что жизнь на тебе не заканчивается