Winning for the sake of winning, merely to be The Winner or to be the one who has won most often, is nothing at all. It is tautological. There is no more significance than to say I want to be tall so that I am tall.
It wouldn't take much to make a desire to win rational. You might want to win football games in order to gain a paid scholarship or to increase your chances for professional employment. You might want to win a sales contract in order to gain a commission or as a step in achieving market dominance. You might want to win a legislative debate in order to modify how the government interacts with a segment of society. If these were your reasons, there would be some substance to your desire. I could agree with you, because there would be something to agree about. Or I could disagree. You would have a goal, whether or not I think your goal is worthwhile. You would have stated a purpose for the effort to win, although I might not agree that winning will get you closer to that goal, Your desire to win would be rational, and it would still be rational even if part of your reasoning later proved to be mistaken. A rational mistake is something.
But to be rational about winning, there must be something more to be attained than just winning. If winning is everything, there is nothing.
Some have said that winning is everything. Even Vince Lombardi, the football coach whose name I know only because he worked in the community where I grew up, is reputed to have said, "Winning isn't everything; it's the only thing." Surely he must have been misquoted. (Actually, Lombardi was probably quoting someone else when he used that line, at least according to Wikipedia. But the record is that he and other people did say that.)
But if winning is all there is, then there is nothing. There is no reason to win. It is vacuous. As Qoholeth would say, it is chasing the morning mist.
I would go farther. I would say this: Winning isn't anything, unless everyone is a winner.
Winning a legislative debate, for example, has substance if the resulting law improves life for all citizens. Winning a football game probably doesn't count, at least by itself. But if the drive to win is part of a larger effort to excel in all aspects of life, and to encourage excellence within the full connectednes of the community, that larger goal could meet the test.
All of this demands the recognition that there is more to actual reality than the category of "winner", and a desire to keep that fullness of reality in play.