I think the decline in posts on this site relates to the camera market in general. There was a boom in digital camera sales a few years ago. When digital started getting close to the quality of film, as well people realized that they didn't have to pay the high cost of film development camera sales boomed. It was similar to the computer and internet boom of the 90's.

Fewer new people now means fewer people looking to figure out the difference in one piece of equipment versus another. The market changed and there are fewer people that do not know the difference between crop cameras and full frame for instance.

Caution, troll example;
The 7d's massive mega pixel density is superior to the 1d X's sparse pixel density. Four years ago (well if the 1d X had existed) I could have trolled that comment and we would have had 40 pages of heated debate. Not today, no one bites.

This site started out as Canon. Most of the people that have been posting on the site for more than a few years are Canon users. Nikon was added not long ago. So yes the answers you get here will be bias toward Canon.