First, no reactors built in the past twenty years (except in China, IIRC) lack those safety features. Passive safety might not be an official standard from a regulatory agency, but is still effectively a standard.
Second, yes, passive safety most certainly does make a plant significantly safer than active safety, particularly when you have two plants right next to one another. Imagine a scenario where a containment accident occurs at one reactor, along with a fire that damages the external power feed to the second reactor. At that point, it is unsafe for people to bring diesel fuel in to keep the emergency generators running to keep the pumps running to cool the second reactor while it shuts down, and suddenly you've gone from one meltdown event to two.