The Gulch or Winding Cove aren't the zones though, the EDZ is the zone. It's even in the name of the EDZ - European Dead Zone. Gulch and Cove are part of the EDZ. To use your WoW analogy - all of Elwynn Forest looks like Elwynn Forest, why do they keep using green grass, wolves, kobolds, and trees... The EDZ is different from Titan, is different from Nessus, is different from Io, is different from Mercury. You are completely entitled to your opinion and I do agree that I wish there was more done overall with the worlds (more hidden stuff, things to explore, etc) but the example of a counter you provided is spectacularly poor. You are asking why do all the trees, rocks, buildings and dirt look similar within what's probably a 10sq mile area of Europe.
It seems like you spent the majority of that arguing semantics even though you understood what I was talking about. I refer to them as "zones" as they're distinctively marked areas on the map. If I was talking about Titan or Io, I would have used "planets". My problem is related to two distinct issues about Destiny's design and art style. The first is that the design lacks good, distinct aspects in areas. If you asked me to talk about the EDZ, all I could really talk about is the church in the one area and the Cabal base at the upper left. (I only know the latter because of how often I've gone there to do the Public Event and had no one else show up... so I had to solo it.) In other words, the areas tend to lack things that really make them visibly distinct from one another.
Talking about being visibly distinct, the second issue is simply with the art style, and this isn't necessarily a problem
just with Destiny. (You've probably heard this mentioned before about other games.) Destiny 2 just has a very boring color palette for its worlds. The colors do actually differ to a degree, but they're always so dull and dingy. I realize that they're trying to make the world all realistic and such, but when the zones aren't interesting due to layout/contents and they're visibly boring, you get kind of tired running around. It doesn't help that you just run from Public Event to Public Event, which there are only... eight distinct events? (I'm counting the ones that I can remember, and that's what I came up with. Although, some of them are so close that I almost forgot about them or are very limited in where they occur.)
Speaking of Public Events, why doesn't Destiny 2 let you talk to people around you in a public manner? It's kind of irritating doing the weapons exchange one, and watching some player that has no idea what they're doing pick up an orb. I just want to type "/s go put it in the the shield thing over there!", but I can't. ...or I can say say "we're at 30%, go shoot the ship!"
especially when you're going around and participating in public events
Running around doing those repeatedly for useless gear usually gets me bored pretty quickly. If I'm lucky, I'll get an engram while doing it, but that's pretty rare. Although, speaking of that, I used to have such bad luck getting engrams (in the past, my teammates would get tons, but I usually got none), but I've been getting more lately... even within raids. Did they change something?