Why only a score of 17 (lenses) on DXO

I don't understand why the really really sharp Oly primes "only" score 17 or so on the DXO.  This puts them in the middle of the DXO poor-to-excellent spectrum.  I see lots of less sharp lenses from Canon and Nikon scoring higher.  Obviously, I have missed something here but can't find a reasonable explanatoin on DXO's web.  I'm sure its been discussed here, but I couldn't find it with search either.

So, what's the story behind these scoring differences?

Thanks for your insights.

Peter F.

(Don't get me wrong... regardless of DXO I will happily be using my 45, 75 and 60 macro.)

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