The danger to having the Latin mass and the VII mass is that you can (note the word, CAN) end up with two groups in functional schism with each other. Each starts to see the other as wrong, or even evil.
I have seen it with the “contemporary/traditional” liturgy split in my LCMS parish. You run the risk of having two churches using the same building.
Just my $0.02
You're right. We need to suppress the Novus Ordo ;-)