I really don't see a problem with enjoying a console's positive sales trends. Seeing a favorite console/handheld of yours see great sales is definitely something to cheer about.
However, when you start cheering because a console you don't own/like is showing negative sales trends... that one I really don't understand. Each console on the market has a part to play, and fans to cater to. Just because you don't like its games/hardware/whatever, doesn't mean its deserving of scorn when it's not lighting up the charts.
And yes, this goes for everyone. I saw it with the PS3 and 360 a year ago, we're seeing it with Wii right now, and PSP... well that handheld has been getting it for a long time now. DS is really the only exception... that thing sells like no other.
This whole cycle of putting down consoles won't end until people (read: us) put an end to it. You think Wii users wont remember this when Wii starts showing big growth this holiday season? So I'll tell the Wii users first: celebrate your console's success, and dont pick on a console when its down. Maybe then we can see some change of heart around here, where people aren't so quick to harp on a console's hardships. There's a place for each console here on VGChartz, so lets celebrate what they stand for and to the enjoyment that they bring to people.