I wouldn't say juvenile or amateur. Just....not what we call a "team player" mentality.
Granted, if you spent a lot of time on a track and thought you nailed it perfectly, would you want someone else messing with it? I can understand the logic, but at the same time....it's one track that could disrupt the flow of the entire album, and that's what ends up looking amateur. I guess it all boils down to what you're trying to accomplish with the album - just doing it for kicks and not really caring if the production quality is perfect or not, or trying to gain attention from the scene and a following with a slick and well-polished compilation.
Certainly neither of those two avenues are wrong. Again, just depends on what you're aiming for.