I don't disagree with the facts here - it has been my experience as well that fighting or fencing, even when one is young and has trained some is exhausting.
For D&D though, I just assume a 1 minute combat round one is not pressing aggressively the whole time, I take it to represent a sort of passage of arms, where many blows are exchanged and one party comes off better than the other... Now I don't think it's very realistic, and don't consider any time in RPGs to be exact. A round is essentially a round, a combat turn, because the game isn't structured around minutes and hours, but around turns.
At the same time it's obviously that the 1 minute round is effectively a legacy of abstracted war game combat - a minute of combat between units seems perfectly reasonable, but when you move it to skirmish combat or a duel it gets a bit long. At the same time I appreciate the abstracted combat it implies. I don't want my D&D combat to be blow for blow, because that just tempts additional complexity. People will want to pull off fleches and disengages, to have mechanical effects added to their choice of faints or efforts to bind. That won't work either (at least not with the existing system), so abstraction that is easy to understand feels about right.
Once one commits to the level of abstraction it becomes reasonable to add some tactical variety - but it's also at high level. Going on the defense, attacking aggressively etc.