I see it more like this: imagine snippets like a packed Christmas gift. You remove the cover just to find out another black pack sorrounds the gift and you get called away before opening it. They let you inside part of the sound, yet with a terribly awful quality and certainly not long enough to make up your mind about it (even worse if the music comes from a band that you know you like). So you arrive to the end of 30 seconds whose passed as fast as ever and you realize you have dozens of emotions playing inside of you at the same time, all of them contrasting each other. 30 seconds seems nothing, but they are already 1/5 or 1/6 of a LT song and so, as EVERYBODY does, you get a first impression of the song without being sure of what you just heared and what has yet to come, and THAT ruins the experience more than everything else. Plus, you don't get the surprise of "going to listen the unknown", where every single note is to discover, 'cause you already heared some and is already not "new" anymore. About someone messing with a leak, I'd just take that risk. With a textured sound like LP is not easy to manipulate something without building up noise in the end, specially when lacking of multitracks. And a good ear can still capture mistakes or even hear if a song was remastered, 'cause it starts lacking of depth.