Adding more water will only thin it out in all aspects. Less alcohol. Les malt flavor. Less hop flavor. Less bitterness. The problem with the dark color and the overly malty flavor lies with the base recipe. To lighten the color, use less dark specialty malt. A tiny amount of some kind of roasted malt will give you a nice red color without adding flavor. But really, a tiny amount. Caramel and crystal malts can add a huge malt profile with just a little bit. If you are using them, cut back. Use a greater load of base malt and less specialty malt. Also, make sure your yeast is completing it’s job. It could be that the beer is underattenuated, leaving it to sweet and lessening the hop impact. Pitch an adequate amount of yeast and let it do it’s thing completely. Take hydrometer readings to know when it’s done.

I’d say the same is true for anyone who puts stuff out there for general consumption. Artists. Chefs. And beer writers.

But here’s the thing with that. Unlike wine, which is pretty much grape-press-ferment and very much dependent on what happens in the vineyard, beer is manufactured. It’s the mechanical operations that maltsters and brewers put those ingredients through that make it beer. The variance from crop to crop is fairly small. The industry demands a great deal of consistency from suppliers, and they receive it. Brewers who know their stuff have all the information needed from maltsters and hop growers to tweak processes and recipes to account for variances. If they miss a number here or there, they have the ability to blend batches. And there are a variety of hop products out there like lupulin powder and bittering extracts that allow for great precision in whatever parameter they are designed to meet. And craft brewers – even small ones – do use these products. Despite minor changes in ingredients, brewers are able to produce an extremely consistent product batch after batch. Think about it. If you order a beer once, you will expect it to taste the same the next time. If it doesn’t, there is a problem. Thus the beer nerd refrain of, “this tasted better last year.”

Additionally, the kinds of issues you mention have nothing to do with the kinds of issues I was alluding to. A brewer could use an entirely different malt and still make a beer that is not dripping diacetyl. The alpha acid percentage of hops could be significantly higher than the last crop, but a brewer worth their salt could still make a beer that wasn’t astringent. Process and technical flaws are only a sign of an inexperienced brewer, not a sign of the complexity of beer.