I know Im new around here, so I wouldn't know enough to say one way or the other, but I have gotten a lot of great information from this site. You don't always have to post something to get an answer. Sometimes just searching can answer a lot. And that could be one way that the site "appears" to be dying… The older these cars get the less new questions there are to be asked.
Honestly though, I don't think its just this site. A few other sites I go on are dying out also. Most have been up for at least 8 years (basically since Fords "unbeatable" vehicles came out, aka the good SVT's). And like I said above, I think the older these cars get the less questions there are to be asked/answered.