I have a theory about why we always seem to get the same top 10 guilds.
1. Mental and Intellectual Aspect of Raiding
IMO Raiding at the very top level doesn't require you to be one of the best players in the world. For example some of the most skilled WoW players in the world is Swifty and Athene (hear me out) You can tell they know their classes better than most people and have got the best natural WoW skill, but would they make it into paragon etc? No, because they would be incapable of following a raid leader. For those who watch Athene and Swiftys stuff, could you imagine them sitting there for hours wiping on the same boss following instructions down to the last detail? No, they would ninja pull the bosses and say 'umadbro'
I am not saying skill isn't important but I feel the mental aspect is more important. You need to be capable of doing the EXACT same thing as 24/9 other players and use your initiative to help out the raid in a sticky situation.
Also you need to be dedicated enough to kill a boss after 500 wipes and still be able to give 100 percent. Has anyone been in a pug who came up with a challenge and they wiped on the first attempt, then half the group leaves even though they probably would have succeeded in the next few tries? Thats a mojor difference between the top guilds and the 'not so top guilds' I am sure there are many guilds out there who are capable of downing a boss, but after 10 wipes the Raid Leader rage quits.
2. Logistics and Planning
Spending hours and hours on the PTR killing the same boss over and over again... The spending hours and hours on week 1 wiping on normal modes over and over again just to get your heroic strat nailed down. Only a few top guilds do this... and they are usually the ones in contention for world firsts.
Seriously advanced mathematical loot distribution charts. The top guilds all have super genius maths wizzes who come up with the best possible way to distribute loot so the guild get the highest mathematically possible DPS. Also have you seen Blood Legions Legendary loot rotation chart? That uses some hardcore math that even I didn't come across when doing a PC Programming degree.
Tactical brainstorming team... Most guilds stick to one tactic and try it over and over again until it works. When I was in a 'top guilds' ventrillo when they were raiding Firelands PTR they had a 5 man tactical brainstorming team with their own Vent channel... They wouldn;t release their corpse and spend the time in between wipes Brainstorming, by the time everyone was buffed uf ready to go they had come up with a whole new tactic to try out. (I know for a fact this is how Paragon operates, also, but on a much larger scale. Each of their members has a private stream so the unused subs on the roster can also watch the fight and chip in with brainstorming... If you are racing for World First you cant just take a 20 minute break to rethink tactics... You need to do it on the go)
#3 Guild Friendship
The most important thing though, is you need to be friendly with your guild and have a good relationship with them. The worst thing that can happen to a guild is it dying from the inside due to people not getting along.
So, my point is, You do not need to be a super hardcore gamer to be in a top guild. I have been in a top 10 guild before (Only in Tier 9, we got world 10th in 25 man ToC and World 25th HC LK) and I am not a super skilled player, I suck at PvP even though it is only pressing the same buttons I use to raid. I am only considered one of the best raiders due to the fact that our guild has amazing planning and we were all friends.