What tonschk said: If you had a time machine and could travel back to the same relative point in time after SH3 was released, you'd find the same issue. Heck, I played SH3 for ages playing with mod soups before GWX was done.
And I enjoyed every minute of it, I should say.
What I'm saying is that the modders' work isn't done yet (it'll never be "done", but what I mean is that we're not yet at the GWX stage), but we'll get there. There's no lack of interest. The stubborn existence of this community over all of those years is proof of that.
We'll get there. Trust me on that one. We are a fanatically devoted bunch.