Well, one reason I think they might have done it is that the monochrome video output is WAAAY cleaner than the smeary color composite output of the A520 adapter. Only the luminance signal with no chroma so you can actually read 80 column text legibly on a composite monitor. The 520 adapter? Eh, not so much. I actually think that the A1000's color composite output is better than the 520 adapter, but YMMV.
