This isn't contrarian; it's dead wrong.
Your starting water pH has little to no bearing on mash pH. Alkalinity does, along with the grist being mashed.
Even in water with low/no alkalinity, with lighter grists some acid helps the pH drop into it's more optimal range.
And that's the "dominant" opinion, which is why mine is the contrarian.
I understand that what you say is how you are "supposed to" do it, but I've never once measured pH nor adjusted it deliberately in any way, and the beers I've been making, including lighter styles like Helles and Pils, have been delicious.
If not measuring and adjusting pH is dead wrong, then the beers I've been making would be bad, but they're not.
Conventional wisdom and some degree of science is on your side.
Personal experience is on mine.
Now, with that said, as I discussed with another chap on this board, we think it may be due to the fact that I don't BIAB or No-Sparge with light styles (or really any of my German Lagers). I usually step mash, starting pretty thick, and batch sparge.
My understanding, backed up with the experience of others, is that full-volume mashing with light grain bills can lead to less-than-optimal pH ranges.
So it is possible that we are both correct, depending on techniques used in the mash.
But without even measuring my pH, I've been producing Helles and Pils that would stack up against anything you'll find in Germany (I spend a lot of time in Bavaria drinking a lot of German beer).
But perhaps it's my process that makes adjusting pH unnecessary.