The competitors always have treated it as a sport. There's a disconnect in attitude between those competing and those judging - the artists. To try to bridge that gap to some extent seems like a reasonable aim to me.
On an earlier point, it's all very well pointing out that musical fundamentals are reasonably consistent within the world of brass banding, but the problem being debated here arises when adjudicators depart from those fundamentals. To pick an example from personal experience: when David Horsfield adjudicated our areas at Stevenage 3 years ago, he stood up at the end and declared that the most important thing that he was looking for in the 2nd movement of 'Festival Music' was a continuous forward flow to the music - and, sure enough, our remarks were full of tellings off for allowing modest rubato in natural places, and our eventual placing was way lower than seemed reasonable - and indeed made the main contribution to our relegation last year after many years in the top section. Had we known he was so down on rubato in that movement, we would have avoided its use; but short of asking him straight out beforehand, we couldn't have predicted that he would be so down on what is really quite a minor point of interpretation - both our musical intuition and existing recordings suggested strongly that a bit of rubato could be used effectively in that movement. If DH had distributed a sheet to all bands in advance containing a line such as "any rubato in the 2nd movement will be heavily penalised" then things may have been rather different...