I suspect the track gauge was arbitrary at first, and scale was nebulous. Quite a bit of older O Scale was done in 17/64, although for most the conversion was simply too tough, when compared to 1/4" scale.
For the vast majority, the difference is not at all noticeable. I personally notice it, and build most of my locomotives to the larger scale. I also have a very small collection of 1 1/8" gauge trains. With the wider tread of O Scale, the sideframes wind up where they should be.
Everybody gets to decide for themselves what to put up with. Josey cannot stand to be missing a data plate. I have a difficult time with U shaped boilers. Some cannot live without cab chatter. Others come unglued when the lettering is not perfect. It is a hobby, not a science.
