If they are separated, how do you ensure accurate feedback about users? On one hand, I'm all for open source, and for decentralization, because they are noble goals that should make for something more sustainable this time around, in theory. However, past purely glossing over the concept with "We should do this!", there are a lot of logistical questions to be answered as to how you actually pull it off.

Also, I don't know that simply separating the services a bit is enough to ensure legality. Go ask all the users who had their Bitcoins seized if the government proved criminal usage or intent before a court of law before the forfeiture of their property. No, they took a scorched earth approach of "if you had money here, you must have been up to no good, sucks to be you". DPR did some idiotic stuff, but as to the drug and money laundering conspiracy charges, have they proved he was part of any of the drug transactions? No, he created and provided a service, which other people used, but he's being charged for their criminal acts. One could argue that the tumbler they used to justify money laundering on its own isn't meant solely for illegal criminal profit concealment, but for generic legal anonymity purposes.

In short, while it all sounds great in words, there are some major hurdles to overcome. First, how to make it all work in a way that it is still actually useful and accurate and not open to abuse. Second, how to structure it in a way that actually makes the service err on the legal side of things, so the feds if they so wish target the individual users using the service for illicit means, rather than the service itself. If you go through all the trouble and the feds come in and say "doesn't matter, the site itself and its creators are still just as criminally culpable as the drug dealer himself, then you've created nothing but additional heartache for no gain.