The torch change is about progression, quite a few of the patches have been in response to people finding money duping exploits via shimmering craftable items sold by NPCs. A big one was the mechanic's timers, which could be broken down several gold bars and easily turned into mountains of platinum very quickly, but it also applies to copper tools and probably anvils next.
Mobile 1.2 strikes again. OK, I see. The iron anvil doesn't work as it buys for 50 silver and components sell for 15 silver, but the copper tools are an issue. I looked through the items sold by NPCs and it does not look like other items have this issue, but I could be wrong.
I do stand a bit corrected though, as the yellow and white solutions do allow making artificial ice and sandstone (though not hardened sand). I take back what I set about the torch change. It's fine.
Hardened sand I think can be made by throwing glass or magic sand dropper into the shimmer, unless this was patched.
In this case, though the torch situation introduced some odd sequence breaks, there was actually some deeper complexity/bugginess with a number of Torch Shimmer recipes in the first place. The items that were created by those torches didn't make sense in the first place. Regardless of sequence breaking, the Torch decrafts needed to be resolved, and this was one fairly clean way to do it without a lot of individualized bandaids for a number of accumulated issues.
Fair enough. At the time I also didn't realize the extra solutions existed.
EDIT: Apparently some of the deeper complexity was torch god's favor. Torches would convert into jungle torches, which could be decrafted into torches and jungle spores, which could then be sold. The torches would then convert back to jungle torches, and the process would continue. The same could be said for basically all of the other torches made by "Torch God's Favor":
Desert Torches produce hardened sand which can be crafted into glass, then mugs, then ale.
Demon Torches produce obsidian which can be crafted into obsidian skulls.
Cursed and Ichor torches produce cursed flames and ichor which can be sold directly (but I don't know if this is made by Torch God's Favor)
Ice Torches produce ice blocks which can be crafted into frozen furniture
Corrupt, Crimson, and Hallowed Torches produce sand, hardened sand, stone, and ice. The ice could be purified and crafted into frozen furniture, the stone could be purified and crafted into statues, and the sand and hardened sand could be crafted into glass, then mugs, then ale.
The only torch made by Torch God's Favor that did not work was the bone torch, as it cannot be crafted (coral torches are not made by Torch God's Favor; I was mistaken here). In fact, shimmering Demon Torches would get you more than the sell price of the torches that were converted, meaning that you couldn't have the torches convert into aether torches + the extra ingredients (you could otherwise buy 60 torches for 30 silver, go to the Underworld with Torch God's Favor active to turn them into Demon Torches, shimmer them, craft the obsidian into an obsidian skull, then sell it for a net profit of 24 silver). So the only solutions were to have a "bandaid" of not allowing shimmering of any torches made via torch god's favor, or the fix made above.
EDIT 2: More information on Torch God's Favor
Late EDIT 3: Typo correction
I can look into seeing whether we could add recipes for making Sand into Hardened Sand/Sandstone. No promises, as I need to get permission for it, but I don't see the harm in it.
That would be a good idea. I would also suggest something similar for ice. Hellstone is still a bit of an issue but a recommendation I had in the balance thread was to have 100 hellfire arrows give 100 shimmer arrows and 1 hellstone bar in hardmode.
Also, does the Crimson/Corruption still convert normal mud blocks into dirt? The wiki says so but I'm not sure if it's right. If so, that's a bit of an issue with keeping the Jungle from being infected.