Even the first-gen iPod was a dud. MS has a long-term plan for the Zune, and it's a few years too early to call it a swing and a miss.
I didn't pay any attention to iPod coverage when it first came out, but if it was a dud back then, then I'm sure media would've panned it for being a dud. Obviously without as much fanfare, as MP3 players weren't as mainstream back then.
Alas, the way technology journalists review products is by evaluating what's in front of them - it's not the practice to take into account long term plans, possibilities and potential of a product.
Nor are consumers going to be any more forgiving of a product's fault just because it's first-gen. They buy a product and expect it to do what it says it does, regardless of whether it's first-gen, fifth-gen or tenth-gen. From an end user perspective, it's irrelevant.
That said, the Zune doesn't have any manufacturing faults or claim to do anything that it can't do. It's just that in its current iteration, it isn't a strong enough product to compete with the iPod.
I don't see that comparing the Zune to the iPod is wrong. It's natural to compare a new product in a market to what's currently available - that's what people want to know as that is what they will base their purchasing decisions on. No one wants to buy second best, and in this field, the iPod has clearly established itself as the MP3 player to beat.