I'm thinking that it's more likely Post Mint Damage rather than a weak strike, because most of the coin is well struck.
I agree with Merc, it is definetly not PMD and is just a terrible strike. '54-s is known for awful strikes. That's why a FS of this year is worth big money. I don't see any part of that coin that is even close to well struck.
I found plenty of nickles that look bad like that yesterday and today. Isn't it PMD because of excessive rubbing in the areas that are faded? That'd be like saying all the buffalo nickles with the rubbed off years aren't PMD. PMD means... Post Mint Damage meaning damage that was done post of the mintage right?
Yes, that's what PMD means. The fact is, this nickel doesn't have PMD. This is the actual terrible strike straight from the mint. Not rubbing or anything like that after it left the mint. That's not to say that other nickels wouldn't have PMD that looks just like this.
Those are what I call San Fransisco "snow drift steps" If you look at Jefferson's hair on the obverse, the low point in the die, you will see the weakness that offsets the weakly struck high point (the step area) of the reverse.