All that would really accomplish (aside from the cross class abilities behind handled differently) is it would make people use a bunch of alts to still have access to every craft.
The macros work because they can 0 to 100 with NQ mats. If SH gets nerfed, and it's still possible using Standard/Advanced Touch and BB, just with higher stats then it would do nothing.
Macros will always be around in some form even if they couldn't 0 to 100. Crafting is turn based, after all. They'd just require a certain amount of starting quality from HQ mats (which is kinda the point of what we're discussing, there's just more than one way of doing so). If SH were nerfed and there was a macro to guarantee 100% (so no Hasty/Basic) with HQ mats (which don't have a macro from NQ mats) then that would be the new standard and all you would've accomplished is making crafting RNG based and annoying (for those that find RNG irritating) for the vast majority who aren't in the very best gear, whether they craft manually or with macros. It's like trying to design gameplay to stop bots (which never works on anything but the weakest of bots) instead of finding the actual issue and addressing that instead (are you trying to stop crafting macros, or do something else with any change that is proposed/implemented?). I will say I much preferred crafting when my stats/abilities were such that Tricks of the Trade mattered - because it changed how I did the craft depending on how much extra CP I could get from it.
The main problem/issue to address, as I see it, is that 80 durability crafts generally have the same quality bar to increase as 40 durability crafts. The progress bar generally does not take 4 extra moves to finish so those actions can be spent on quality (and the extra max durability makes it easier to use longer duration buffs or things like Master's Mend II and just generally be a bit more flexible). That's why there isn't a macro to 100% 40 dura crafts from NQ mats - because those crafts actually function fairly well with the system/stats we have at the moment.
All a matter of whether the devs see it as a 'problem' or if the current ease of HQing things is working as intended (higher crafts to eventually be added after all). Also the matter of people HQing gear when leveling to consider (especially for class quests - would put higher emphasis on starting with HQ mats, though).