This is where I see the problem...
Let's say you lend me 0.01 BTC, and after a month I return you 0.01 BTC. 
And then you tell me: “Smartprofit!  I lent you 0.01 BTC that I mined myself, and these satoshi are readily accepted by all centralized exchanges!  And you sent me 0.01 BTC, which has a history, and this history is not very good.  This is not a fair exchange because I will now have to spend some effort in order for these satoshi to officially become “white”.  And from this point of view, 0.01 BTC is not equal to 0.01 BTC!” 
Yes, this is not what Satoshi Nakamoto intended, but, unfortunately, this is the modern reality.((( 
I have different satoshis, and if in relation to some satoshis I have no doubt that I can easily turn them into fiat money, then in relation to my other satoshis I have doubts that it will be easy...
At the same time, I do not  a criminal and is categorically against breaking laws.  But even if you follow all the rules and laws, you can still get officially “dirty” satoshi.