Personally I think the same of Discovery as any other being here. The only reason they had such a good number of people on their server is cause of the new version they released. its always like that in humanity. If something new is about to get released, a few people start showing lots of support and try to spread the support with news and rumors etc. When the thing gets released then all of the sudden on day one its overcrowded cause the people have something new to play, look at (and drool) and then after a few weeks or months it starts getting old and the lesser loyal people start vanishing.
But also I played Discovery once recently and it didnt last longer than 15 minutes on my pc ....it just doesnt have the feel and fun of the mods made and supported by swat development imo