It was a comparison of "the" performance bikes of the time. Kawasaki just happened to have 2. We all know the triples were basically no more than "door openers" for Mother Kawasaki to get in the motorcycle game as the new kid on the block. Build em cheap light and quick for the hearts of the American drag racers. Get em brand loyal, and get them on Z1's. I'm sure Mother Kaw had heaps of warranty and troubles with the triples, as they were made to get beat on, and broke a lot. And made for a short life span, and disappear into Coors beer cans......
That being written, the mag "had" to use both bikes as they were both "performance" bikes, just in different ways. Could you imagine the backlash if one was left off this historic test?

So as it was, apples got compared to oranges. (and a couple of loose nuts)
Two different bikes and philosophies, in the same test. Of course the Z was a better bike in most respects, as has been iterated here. The H2 had something the Z never could have, the sheer untrained animal heart of excitement/fear. (for the time...

)
I like most went from a triple to a Kawi 4 for the comfort and civility. But always had a triple around for the sheer excitement factor of rattles and shakes, smoke, things falling off, numb hands and feet, wheelies galore, knowing the gas station attendant by name, and the wonderful thought always in the back of your mine, will I get home on this thing!
I think we were all licking in the fact, that were lived in a time when they were both new, and in a time, they are still going strong. I don't the the newer generations had anything like these gals in their lives that meant so much to us, for just being motorcycles.