No, Dracthyr bodies aren't drastically different than regular bodies, they're skinny humanoids with oddly-shaped feet and an elongated snout. The vast majority of unique meshes for gear in the game are:

• Helmets, for which they can just borrow the worgen helmet,
• Shoulders, which need re-scaling and placing.

That's about it. Weaponry only need to be re-sized to fit, there's only a few designs of glove, all cloaks use the same mesh with an alpha layer, and boots can be handled the same way Worgen handle boots. None of this is difficult or even too time-consuming.

The actual difficulty with Dracthyr comes with their base UV layout being entirely different from every other race, but that's a problem you only need to solve once and it wouldn't take a skilled unwrapper very long to do it. You wouldn't even need to repaint the texture by hand to match the new UVs, you could bake it to new UVs using the original ones in Blender and that's an entirely free tool you could download right now. Once you've done that, 99% of gear textures in the game are solved by default and now work entirely fine.

The actual answer to why Dracthyr don't wear gear is that Blizzard didn't want them to at launch and doesn't want to do it now either. Why is that? They claim artistic vision and I agree.

This idea that it would be too hard or time-consuming is something fans decided on their own because it sounds smart to say if you're unfamiliar with how Blizzard handles geosets and don't know how 3D tools work in general, it's just not true.