With all the open world and alliance content that has been released, I'm surprised this hasn't been addressed before. The problem is twofold:
This has become a issue again in Eureka, and remains a problem in 24 man content. You should be able to apply filters to customize what you want to see, both on the target bar and focus target bar.
- You cannot see your own debuffs and dot timers.
- You cannot see targets buffs, especially a problem when you need to see things to do mechanics.