@Tesumph
You have to remember that zucchini is secretly very similar to pumpkins. They're from the same family and can even hybridize with each other. So it's not actually much stranger than pumpkin pie. Zucchini has a nice mild taste with a light sweetness and the sweetness really comes out when you cook it certain ways, much like pumpkin. When you grind it up and put it in a quickbread (like zucchini bread or the cake listed here) it adds some nice vitamins, texture and flavor to it. It compliments it really well. It's a little like carrot cake in that sense.
The other thing is zucchinis can produce like crazy. My record weight for a zucchini was 7lbs 10oz. We sliced it into 3/4" thick slices, seasoned it, and grilled it as "zucchini steaks" at a cookout. Eventually, when you've gotten 10 5+lb zucchinis in a year, you need to find clever ways to cook 'em!
Still, the recipes for zucchini bread/cake have endured in ways that zucchini noodles and such probably never will, because they really are very tasty and the zucchini is a really nice compliment. I remember when I was a wee child and I "hated" zucchini, but I would eat zucchini bread because it tasted like banana bread.