I for one don't think it's that important. Let's think about it. The only reason for such a quick change would be to catch some serious mechanical issues before they destroy an engine. For example, they pull the filter at 1200, and find an unusual amount of metal filings. BMW can now pull the motor apart, determine the source and correct it. Motor saved, and you're none the wiser. We know the oil is still good.
Having said that, I checked it before I bought my car (it was used too) and chose not to buy one because it had been done way too late. This points to a careless, non-passionate car owner. IE - not someone like you and I. Not really what I was after, but I still don't think it would have any significant long term effect. YMMV.