I honestly don't think making Toxikon even more useless than it already is would solve the issue.
I don't even think these players are fishing for Toxikon stacks in the first place, I think they simply have no idea how to play the job properly.
How many Whitemages have we seen over the years who let you die because all they cast is Cure 1, even far beyond the level where you gain more powerful spells?
How many Whitemages have we seen that spam Medica 2 for every little bit of damage?
I think it's simply the exact same case with these Sage players. Despite long time healer mains hating how copy&paste it's design is, it is popular among the general playerbase, second only to Whitemage.
So you get a lot of players on the job who think that every AoE needs to be shielded because they don't know any better.
It's really no different than the occasional SCH that casts Succor every 15 seconds for basically no reason, Sage is just more popular and consequently the bad Sages you encounter more numerous.
