Ok, Fine. you think water chemistry is easy - tell me 5 other things that are part of home-brewing requires more technical expertise and scientific knowledge, and bring a lot less "bang for the buck" and yet we talk about it constantly. that's the topic of this thread - it's not that it's useless, it's that it's too much work for relatively little benefit.
To me water chemistry clearly one of the most, if not THE MOST advanced and complicated topic of home brewing. I can easily list 20 other things that any beginner or intermediate brewer should do before they even think about chasing Edinburgh or Pilsen water profile, assuming that's the ideal and necessary composition to make a decent Scotch Ale or Pilsner.
Calculating water profiles and plugging in the bicarbonate/sulfate/chloride numbers into a spreadsheet combines the fun of filing taxes and having a root canal, without all the fun of tax refund or anesthesia.
Having routinely done all three (yes, I do actually use Bru'n Water and Beersmith water tool quite a bit - and I vorlauf too, but I still think its overrated), I wouldn't recommend it to a friend who is into brewing as in "Hey, this water chemistry stuff is so much fun, very intuitive and super-easy to understand too - you should totally do this!".