They're young, but that defensive line has some potential talent on it after they parted ways with Allen and Williams. We don't really know what Griffen is capable of in a full time role and Floyd was a really highly regarded prospect at DT. Their secondary is in the same boat with Smith really showing something last year, and Rhodes and Munnerlyn could be a decent corner pairing.
It's all potential at this point, but Vikings fans are probably just as hopeful about their D as Rams fans are about their O.
Which is not to say the Rams won't destroy them in week 1. But we should take pride when they do!