I don't have time to read through this whole thread, nor do I disagree with the IP. Since the last revision the forum has been a confusing and convaluted mess that I rarely use anymore.
However, there are many other factors for myself:
1) The loss of all the chart functionality
2) There just isn't much to talk about. Wii is dying. 3DS is stagnanted. PS3/360 have nothing interesting going on except for #3 of the same old games. The industry is dull at the moment.
3) This is a site that was all about which system is selling the best and which games. At this point, there's few surprises or arguments about any of that. Again, the lack of all the chart functionality hurts.
4) Lame articles. Sorry guys, but far too many are lame. This isn't the only site guilty of that though.
5) VGChartz is trying to spread itself too thin and become another generic games site and has lost much of what made it different and interesting in the first place.
6) For me personally - loss of the Nintendo crowd. There's some still here but the vibrant Nintendo community has grown mute as there's little to discuss aside from Nintendo's problems.
