AVID is really, really archaic.....
You might not be saying that if you were working on a project in which there was a good deal of metadata that needed to be passed on through the post process (ASC CDL values, for instance - try that in either Final Cut or Premiere Pro......) and not be subject to loss if a project file got corrupted. The idea of MXF files is that they can carry rich metadata and that metadata is contained within the file itself, which means that even if the MXF file gets renamed, it will still relink to any timeline that has used that material (try that if you don't believe it). Avid is all about metadata and media management, and that is the reason it survives and thrives in the professional world, especially on larger studio projects where the things I just mentioned are not only expected, but often critical to the process. And yes, making proper use of those things sometimes requires a bit of extra effort. But the payoff, particularly on larger projects, can be substantial.