I opine that, in general, bikes sold for racing purposes (road or mountain,) are sold with stems that are far too long. In fact, as an employeeeee of a bike shop, I would much prefer it that bikes were sold without stems, and that it be up to the shop and the customer to find the right length. Of course, this is essentially impossible, but still, I think most riders would be happier with a different stem.

Furthermore, it is not so much the size of a rider, but his desires. Which kind of rhymes. His priorities. His hopes, dreams, and wishes. If our Scott-framed friend above were to desire a ride with a touch less whip, he could shorten his stem by 20, 30, or, from the looks of it, even 40 millimeters, and would thereby be blessed with better tracking, at the expense of a bit of the bike's agility. If he were to put, say, a 50mm downhill stem on the bike, it would be a poor fit no doubt, but reducing the length by a couple of centimeters would only change his riding position, likely for the better, but would give his venerable carbon beast a little more trail-worthiness.

I am also a fan of riser bars, but perhaps they have no place on that bike.