Since, right now, there are only 2 option in the game (fort fighter and dueler), the potion have no good use. 99% of the times people changed attributes and skills was because of the quests. Right now everyone can do all quests (there are a few with special requirements but just a few bonds can buy instructions to solve that matter) without needing to get skills into it. Construction is just for a small group and very very limited in time.
There are many options other than dueler or fort fighter. Many people like to do jobs and have builds which let them to high difficulty jobs at low levels and at very high LP later on giving them good xp/cash. They still use the work instructions to add to their bonus. Then there's the pure trader/FMS build for those that like luck jobs and getting high value items from jobs. Other pure builds like hiding or shooting/trapping are not very popular now because jobs can be done with levels, but people still use them to try different things and change builds. Builders may be a small group but many people change to duelers and back, many people with other builds change to builders to help builds towns/forts and then respec back to their old builds. Even for a dueler/fort fighter there are different types of builds and people change skills to experiment what works best for them. For all these people, these potions are very valuable.
I support this idea because the people that don't actually need these potions shouldn't be forced to hold on to them as a show piece in their inventory.
There is a potential for slight abuse for those that can buy it for bonds/nuggets and sell on market, but those that want to do this have much better ways of doing it in the form of chests and other items, and IMO bonds/nuggets are more valuable than in-game cash.
