IMO, the moral should be keep things tidy, the same if you received dust or not. Although a single point of failure is enough to break your privacy, the more mistakes you make the more chances of being tracked and, eventually, attacked. So it is a good idea to create throw-away addresses while being aware that every time you consolidate you may be sharing too much info.
I don't know how scammers manage to know which wallet has some funds in it to target, from what I heard they send lots of micro transactions to multiple addresses, but how do they get this addresses, are they guessed or is they a way they find them.
Every addresses are made public once they sent out some coins or they receive some coins, for example every coins have their block explorer, even if you get a new wallet today and you send some coins from an exchange into the wallet it will be visible on Etherscan and others. ..
Once it sends or receive it become public and others can view how much tokens and coins you have in the wallet, what they can't find out is who the real owner of the wallet is, so scammers can send fake tokens or NFTs to the wallet, hoping that you take a step.
Most people got scammed this way because they got greedy, seeing free tokens in their wallet will make them misbehave, they will start finding ways to sell the free tokens or coin, and this will lead them to the wrong or malicious link where they will end up getting scammed.