^ This. Having too many "Useless" addons available to the player imo is a useless observation. If it's as useless as you claim, then don't use it. My love for addons is more in line with what Callinon is saying here. I'd rather spend more brain cycles dealing with the encounter than futzing with the UI. But more importantly, with me, it's about data. I want to have useful data in front of me. So damage meters (though a nuisance when abused) are useful to me because they give me feedback on *what* I'm doing. Or when raid leading, I want to see a report of effective healing because they tell me something about my players and more importantly, they tell me something about the healing arrangements or the fight itself. Or an interrupt report which can tell me that we're getting our faces handed to us not because we're undergeared or sloppy, but people are missing interrupts. Cooldown timers are nice too. In ARR, I can't tell which DoT icons are mine by looking at the target. I could run a /recast macro, but that can be hard to read in a window.
As far as healbot goes (for me anyway), I always healed out of the corner of my eye for the most part because that's all it really took for raid healing. For tank healing, it was about feeling out the flow of damage, prepping for expected spikes, and various other stuff, but it all came down to being able to target quickly. I shouldn't have to fight with targetting just switch targets and get a heal off quickly. ARR's targetting is unreliable and generally ******, to be honest, so I feel there would be a great gain from this addon. This leave some brain cycles for keeping an eye on where I'm standing, raid warnings, cooldowns, etc. Of course, one could possess the skill to do all of them at once without the use of addons (and I do this daily), but honestly, I'd like to be spending my thoughts elsewhere in the encounter.
It's a preference thing. You really don't *need* any of these things, but I want them. Regardless, you really can still tell the boys from the men.