Because everyone's definition of taint is different, and coming up with a globally recognized universal definition of taint is logistically impossible. To you,

Because everyone's definition of taint is different, and coming up with a globally recognized universal definition of taint is logistically impossible. To you, you might be trying to break your link with a Bitcoin mixer by wrapping those bitcoins and uniswapping them for a different asset on Ethereum. To me, I simply went to Uniswap and bought some wrapped bitcoins, then deposited them on a traditional exchange.