It's pretty silly that SE goes through the trouble of designing these massive zone bosses with their own FATEs, achievements, and unique rewards, and then a month after each expansion launches they remain untouched 95% of the time they spawn (excluding FATE parties, which occur only in certain zones and even then often don't have the numbers to challenge the zone boss.)

It's not a perfect solution, and I know the idea of encouraging FATE participation is anathema to some people, but I figure it can't hurt to suggest these bosses reward a small amount of Allied/Centurio seals (maybe a smaller-than-A-rank chance for a mark log/crystal cluster?) when defeated. The exact amount rewarded would be up to SE to balance, but I feel like treating these guys like mini hunt mobs would do enough to encourage people to kill them and maybe give the people who never got to fight them an opportunity to actually see the FATE to completion.