If you bought a camera up until the late 1990's the lens you were probably getting was a fixed lens, usually 50mm. It wasn't until autofocus in SLR cameras not only got better but cheaper and zoom lenses utilized this autofocus did consumers really clamor for zoom lenses.
Zoom lenses are a really interesting engineering problem. In order to have a lens that can focus as wide as 35mm and as far as 70mm you're going to need to make some sacrifices. First the aperture is going to need to be higher to keep the size of the lens down, you'll notice most zoom lenses with a low fixed aperture are really expensive and much larger than standard zoom lenses. Secondly you can't have sharpness throughout the range, so you can shoot at 35mm and 70mm but the image quality usually differs between the two. All these critiques are technical and about tradeoffs but what really turns me off from zooms is how they are typically used.
With a zoom lens you can cheat a bit more. Many years ago I was living in Boston for graduate school and went to go see the Boston Marathon. I sat on a corner with my friends cheering and taking a bunch of pictures. With my zoom lens and good view I could snap away, zoom a little in here and zoom a bit out later.
These shots came out fine, I captured the event but the biggest issue is I didn't move. I sat in one place the whole time. And that is why primes and especially a 50mm lens, closest to actual human field of view, was so instrumental in my development as a photographer. In order to get closer with a prime you have to physically move in and out of a shot. If I wanted to get closer to a runner I'd have to stand in the street a bit. If I wanted a wider shot, I'd have to go back and possibly climb some stairs.
This act of moving opens up options too. Now I'm in the street, maybe I can crouch a bit to to get a different angle? Maybe I should go over to that bench and get an overhead shot? This is how I learned to use my legs and position to develop different shots.
The physical act of moving toward a subject and away from a subject changes the images too. Getting a tattoo shot five feet away and one foot away are totally different things and encroaching on different personal boundaries. Being that close because you have to adds a tension to the image that otherwise would not be there.
There are always exceptions. You can get a really good zoom lens, like a 24-70 F2.8 to overcome the issues with cheaper zooms. For professional sports and fashion photographers who work in confined fix spaces most are sporting 70-200mm F2.8 that comes at a pretty high cost.
Photographers with zooms can actively think about moving around more and using different positions too. The trap of zooms is that using it to get closer and farther made me focus on one aspect of the image, distance. Using a fixed lens made me think about movement and relation to a subject. I saw my photography get more creative and more personal the more I used fixed lenses. Instead of sitting in one spot and capturing the world with a zoom, with a fixed I had to physically approach if I wanted to get closer. It get's your butt out of your seats and out of your comfort zones.