I do agree that some brewers can get lost in the minutiae of adjusting all the fine details on their water. Where I disagree is that finding a good-tasting source water is sufficient for all your brewing.
I have a well with good-tasting, relatively soft water. There are some water adjustments that I make, where I think it improves the finished beer, but the difference is small enough where it could be considered a minor tweak and the beer would still be pretty good without it. But there are a few beers that absolutely require adjustment on top of my existing water or else the end result is lackluster.
For hoppy beers, I need to add sulfate to get to the 150-200ppm range for my tastes. I've tried it without sulfate and the hop character just falls flat, and in the 300+ range it becomes too much for my liking. For roasty beers like stouts and porters, I need to add baking soda to get in the 5.5-5.6 mash pH range. At lower pH ranges the roast character is muddy, while at higher ranges I get the roast character that I'm looking for.
So, while I think it's easy to get caught up in the small stuff (especially if you don't understand water adjustments very well), you still need to pay some attention to your water to make the best beer possible. Just like with cooking, proper balance of salt(s) and acidity will enhance your beer and highlight the flavors you're looking for.