So it’s to keep the already inflated QB points scored down to a reasonable level. It doesn’t matter, as long as you know going into the draft then you know what type of QB to draft, but with 6 pt per TD the pocket QBs become more valuable than the running QBs or at least more equal to them thus making the risk of drafting a dual threat QB not worth the pay off IMO.
Everyone that drafts a running QB knows any play your season with hi could be done, while pocket QBs still can be injured it’s just not as frequently.