Consistency comes at a price…
There's an old saying in manufacturing: "You can have quality, speed or low cost. Pick two."
Discs are made in such quantity, that there isn't much time to perfect the process for each run of disc or plastic.
I don't think anyone is arguing that it can't be done, the discussion revolves around if it is economically profitable.
It would be interesting to see if any of the numerous new disc mfrs tries a new business model around the balance of guaranteed consistency and at what price.
Didn't 1 disc company use to stamp batch info on the discs? This doesn't add quality but it would make it easier to find similar flying discs, based purely off plastic.