Morally we should be avoiding Russia, and treating them like a pariah.
If we want to grow the game in an ethical way, I think we should be looking to host it in the US or Argentina.
Sadly morals and ethics don't come into it.
If it did, would China have hosted the Olympics.
I don't think we should tarnish a whole nation by the actions of the elite.
The primary thought to consider is whether a country can offer the infrastructure to host incoming fans and move them around the country from location to location. I think that rules out Argentina
Russia proved they could do that in the football WC. Oz can do that as well but there are doubts about the state of rugby union in Oz and the willingness of the elite to invest to make that happen.
I doubt Russia has a vote on the World Rugby council.. but they know how to make an offer that can't be refused.