Exactly. Very repetitive music that covers much of the spectrum can be seen as a more enjoyable form of pink noise. The effect is to mask all other sounds you receive and to create an environment where no aural cues interrupt your attention. Once your brain has realized it's not going to receive interesting data from your ears it stops wasting focus on interpreting it.
There are very good reasons why people would need this. The "uniform noise environment" point has already been made. One poster noted that tinnitus sufferers need some kind of aural stimulus or they get hit by a distracting high-pitched squeal. Then there's a condition called hyperacusis - the sufferer is overly sensitive to sound, being easily distracted or perceiving sound as too loud earlier than most. A variant of this makes it hard to ignore any sound, even quiet ones - they automatically command the sufferer's attention. You can imagine what this does to the sufferer's concentration when someone nearby talks.
Developers need to dedicate as much mental capacity as possible to a given task, especially since they need to keep many different bits of information in their head at any time. This makes noise insulation a good idea. Noise-dampening headphones (in-ear phones or the big earmuff-types) can reduce reasonable external noise to a point where music or white noise at a sane volume will completely cancel most of it.
If music privileges are to be taken away, I recommend issuing passive noise-canceling gear to focus-oriented workers or installing pink noise generators to provide at least some form of noise suppression.