Jilerel, the D&D forum wasn't discussing rationale for preferences in flair or style, but the mechanics of modelling for either “CAS” or “CAW” with D&D rules.
There is no such thing as war or sport.
Perhaps you meant that there isn't a dichotomy of « War – Sport » insofar as the two aren't on the same metaphysical level, or so. To that I agree, but see below.
Candy, you most certainly can develop fundamental rules that support both systems — just depends on how you structure the rule environment and what player interest–themes you are accommodating; do you want to restrict players from cheating in sport? or are the players capable of agreeing per each engagement as to how they will conduct it? et c.
Kaerli, interesting read, but I've seen this as a much broader consideration than simply regarding Combat and Sport, and most people here aren't interested in expanding and redefining their ideas for what role–play is or could be, or why most RPGs aren't proper role-playing games anyway.