Bittrex gives new coins a chance like no other exchange i have ever seen. I'm sure its not easy loading and unloading new coins all the time and they are to be commended for what they have done so far. They are bound to get some wrong once in a while, but most of the coin decisions look to be from volume and community participation metrics. Crying about your coin being de-listed is pretty pathetic when you should be working to keep it listed in the first place(if it's getting de-listed it's probably a sign).