Wasn't aimed at you. They know who they are.
The vast majority of times I've seen it used in practice, the raid leader assigns buffs to specific paladins. These players often being the ones who don't understand which specs should get which buffs (like giving a Holy Priest Wisdom instead of Kings because they already have Sanctuary). That's assuming you can get them to use their buffs at all without having to spam them or yell at them.
Then I, on the other hand, when grouped with a raid leader who knows me well enough will almost never assign me to a buff because they know I will always provide an appropriate one without being asked.
I'd say it's a pretty distinct difference between having an addon track a proc and having an addon that tells you to use Crusader Strike next.
I've confused it with my buffs on live then. Either way, more than long enough to outlast any boss encounter.
I don't consider rebuffing after every fight where someone died, or after every 2-5 fights (not exact numbers) to be too much to track. It would be easy enough to track your own buff as a timer, and then rebuff everyone when the group's buff is about to fall off. As for wasting mana, do you not like carrying water or utilizing fish feasts to refill your mana? And wasting symbols? I always carry more than enough for myself and enough to provide any other paladin enough to get through the raid as well. Also, do you care to bother reconfiguring your addon every time your buff assignment changes? I guess you consider it a lot of work to pay attention. I don't. I understand that plenty of paladins like not having to pay attention and just yolo swag zerg dps like they're a warrior, because that's an easier approach (both in practice and in understanding), but that's also not how I play the spec. To which I will say: to each their own.