Torture works a lot better if you know what you're looking for. With BTC you know exactly what it is you're looking for and how much. If all you know is they paid with a privacy coin then you have no idea how many wallets they have or how much money, there's no more advantage to giving up 2 wallets than 1 as there's no reason for an attacker to not think there's a 3rd you're holding out on if they didn't believe you the first time -- the options would be give up everything and get blow torched or give up only some and get blow torched