That is a mistake Blizzard made and should fix. The achievements and titles should be different for different things, e.g., different for 10 and 25.
Being an achievement whore doesn't mean that you're automatically entitled to every achievement. If you're an achievement whore and prioritize that over everything else, then you'll obviously raid 25 mans to get those achievements. You can't expect to only raid 10 man and be given all achievements just because you choose to call yourself an "achievement whore". That's like saying you don't like grinds but because you're an "achievement whore" you should be given those achievements without the grind.Ever heard of the term achievement whore? Whole the content is relevant instead of a patch later?
That's not what I asked and it's irrelevant. I asked how a single person can take responsibility for the whole raid in a 25 man like (s)he can in 10 man. Of course there's delegation in 25 mans, that's how you do it. But it means that you must find people capable and trustworthy enough to delegate to, which you don't need to do in 10 man. Again, you need higher skilled people in 25 mans.There is no simple and easy answer to this and I cannot tell from first hand experience in WoW context, but I can tell you from first hand experience IRL context. The keyword is delegate tasks (I think, delegation it is called in English).