That's true yes. But a bad trip can be (and most of the times is IMO) much more ''intense'' than a normal trip.
For me darkpsy that deals with negative emotions, depression, nihilism etc. (which is only the 5% of darkpsy) is simply trying to express all of these through music.
I can't understand why can we have tracks about love, but not about hate. Tracks about happiness, but not about depression etc.
The problem starts when cheesiness and corniness enter. If a track has samples about virgins sacrifice, or Satan fucks God etc. then yes it's so cheesy and stupid and all the artist's effort to create something really dark fail miserably.
But when it's made in a good way I can't understand why bash these artists for exploring the dark side of life.