Yes it is.
The spec could have been written such that different capabilities were reflected with different physical characteristics. That is exactly what standards exist to do.
Even if we pretend spec writers wouldn't ever have predicted the proliferation of crappy cables before publishing it, this is not a new problem with USB.
It is absolutely a choice made by the USB Implementers Forum.
And the cheap knockoff brands would have just violated the spec written that way like they violate the current spec.
This is why some things that have a C port won't charge on a C-C cable, but will on a A-C cable, because they don't actually talk to say they need power, but the A port will provide some power regardless, but a C port won't.
Power-only cables should be specified to have a different connector. Vastly different speeds should have a different connector. It should be physically impossible to stick the wrong kind of cable in.
Third parties will make out-of-spec cables no matter what. Some of the ways that Apple has addressed this is the "Made for" program which goes back even to the iPod. And the devices themselves detecting and showing an "Accessory may not be supported" error message, again going back to the iPod.