You bring up a very interesting point. Are many of the negative threads in this forum largely influenced by the negative after-effects of ecstasy? I'm sure of it. Are they valid, then? Definitely. The change in brain chemistry makes a lot of people focus on negative things. But while on ecstasy (specifically in my experience, MDMA), people focus on positive things--increased value in bonding, physical sensations, enjoyment of dancing, etc.--and do we consider that something valuable? Of course.
I don't mean to make a lengthy post on this, but your observation brings up a HUGE part of my thoughts on mind-altering drugs in general. I feel that the reason ecstasy is so valuable in my life is because it makes me look at things differently. It has taught me to value the people who are close to me on levels I was ignorant to before. Just as importantly, it has taught me how to deal with negativity, and subjectively analyze my emotions before they influence my behavior. If people have emotional comedowns, and think to themselves, "oh, these emotions are just because of the drug, they aren't real," then the drug has done nothing for them. Those emotions are as real as any other. They may not be rational, but are cuddle puddles rational? Of course they aren't. People who aren't ignoring their emotions, and instead choose to post worried threads on here, are on the right track to really getting something out of this drug. They are learning something about themselves. I LOVE seeing all the stressed-out threads with kids working through their thoughts. It's just as important as remembering their awesome weekend. And for those who have truly shitty comedowns, they are doing themselves a favor by not ignoring themselves (or drowning the bad effects with more drugs), and considering that maybe ecstasy is not for them. If more people stopped when their body told them to, I'd imagine less past abusers would have depression/panic disorders today.
I don't think the forum is so sad on mondays and tuesdays. It's a good sign.