Decentralisation is the point that makes bitcoin safe. It prevents that the blockchain is altered. So exactly this point prevents abuse.
Decentralisation has nothing to do with anonimity. Anonimity is based on the fact that there is no connection between an address and its owner.
Everybody who is in the crypto business is doing so on his own free will, nobody is forced into it.
If somebody loses money here, that is the risk he was taking when he entered this world.
But to be fair, I think that regulations are needed everywhere. On the streets just as here in the crypto world.
Regulation always sets a precedent, some of which can be extremely dangerous. There are often times where "acceptable" regulation allows for more severe infringements in the future. The question is where you draw that line, and in almost every case I have seen, outside of some form of professional/safety regulations, it is almost always a bad thing to have a government involved in regulating anything outside of safety measures for economic activity. While I can agree that there is an issue within the community when it comes to having websites shut down without warning or a getting scammed, that's just a fact of life and there's nothing that can really be done about it. Sure, you could "regulate" these activities, but how would you even go about doing it? The concept itself is ridiculous, especially in a pseudo-anonymous and trust-based community. You can't regulate something that has those characteristics tied to it.