Except in cases where someone doesn't know the direction the market is going to go and is trading each side separately, I don't know how hedging provides an advantage.
From my experience, sweeping generalist value statements are fraught with danger. I'm personally guilty of it but I try to be mindful of it.
But hedging with purpose as part of a core strategy makes all the sense in the world.
I've seen a number of traders over the years who nursed along a loser with a "hedge". In the pits we used to call this a "Texas Hedge" and it wasn't a compliment. Over the long run
if you are trading outrights as your original intent and strategy from my experience it is almost always better to just take your lumps and move on the next opportunity rather than to belatedly nurse along your stinker with a "hedge". I don't call this "hedging" - I call it an excuse for bad behavior. In that context I agree with your contention most wholeheartedly.
But as you alluded to in your OP, and for the purposes of a general explanation to other Members, there are perfectly good reasons to hedge as a core strategy.
In the 1990's I traded commercially for one of the biggest electric utilities in the country. We were both producers (power) and users (fuels) on a large industrial scale. Hedging was the reason for our trading desk's existence, and the value added price improvement we personally added was the basis for our bonus structure.
There are a number of options vol traders who choose to use strangles and straddles in order to help minimize the effects of theta decay. In fact, hedging is an integral part of many options strategies.
Just about any arbitrage and basis trading strategy that I'm aware of involves hedging.
There are countless relative value hedged equity portfolio strategies.
And near and dear to my heart, there is the inter and intra market futures spread trade.
All of these examples I cite above have a common denominator - the hedge is a core component of the strategy and not an afterthought. The idea is to capture convergence or divergence between two or more highly correlated instruments.
But it is not an afterthought crutch for faulty hubris.