Hussar
Legend
I would say that warforged fit perfectly in Eberron. However, the only reason for that I can see is because the author decided there should be warforged in Eberron.
Of course. That's the entire point. Silvanesti Elves fit where they fit because the designers made them fit there. Now, some races are generic enough to fit pretty much anywhere. That's true. But, being designed to fit in a particular setting isn't a problem. It's not like you are being forced to accept Warforged in any other setting other than Eberron. There are no modules featuring warforged in Greyhawk for example.
The complain is that warforged don't fit in DnD. Well, my response is, Warforged fit perfectly well in Eberron. While Eberron may not be everyone's DnD, it's still DnD. It uses most of the same mechanics as any other setting. There may be some changes, but, that certainly doesn't make it "Not DnD" any more than Athas is "Not DnD".
Or, look at another way. Hollow Knights are listed as a player race (with a rather whopping level adjustment) in Scarred Lands. Storywise, they are pretty close to warforged - a race of sentient constructs built to fight a war. Although they were built by gods in SL, most of the rest is pretty much the same all the way down to the idea that they are trying to find a place in post-war Scarn.
Does that make SL a bad setting? Does that mean that SL is "Not DnD"?
As far as airships go. Well, lets not forget Dragonlance had flying castles. Floating battle platforms from which to wage war. That's about as solid a Space Opera SF trope as you can get. Would anyone care to claim DL is not DnD?