Any sufficiently advanced technology is indistinguishable from magic. Arthur C Clarke

Railgun is epic

"Any sufficiently advanced magic is indistinguishable from technology."

— Larry Niven's corollary to Clarke's Third Law

Why do we have this exact same conversation every damn week?

An arms race, or the fact that magic is, for many races, "easier" and better understood, and the tech is already a bit throttled. Why make a machine to do what a simple spell can already accomplish? The reverse is also true, though, for the more tech-inclined groups, which I think works with the lore of Gnomes learning the Light from Dwarves and Humans. They've had medical tech for years, but using healing magic was slow in arriving to the society until the exodus from Gnomeregan necessitated finding other ways that their neighbors understood better.

I like the mix of tech and magic. Sometimes that incongruity actually does make it seem more "realistic" from a roleplay perspective, and makes sense for the world; magic doesn't preclude the advance of technology since not everyone can use magic, and vice versa.

Honestly, WoW would probably be less popular of a setting and game if one or the other was too predominant. It appeals to a wider audience. I know players who don't like pure sci-fi settings, and others who aren't interested in pure "traditional fantasy" settings. The mixture is different enough to appeal to people who like both.

"Any sufficiently advanced wormhole generator and mechanical vendor is indistinguishable from a mage."

I've said it before, I'll say it again...Azeroth is not medieval Earth. Azeroth is not any other established fantasy setting. Azeroth is a world that has been shaped by entities known as the Titans who used technology in their work (as is evidenced by their bastions of antiquity), and the Azeroth exists within Blizzard's own intellectual property universe. Any attempt at shoehorning that which is in the game into any other mold is folly.

To that end, don't worry about the technology. If you don't like guns, or flying machines, find another fantasy world that suits your desires and preconceived notions.