Let's just clear up some myths. There is a myth that small guild bonus gives an unfair leveling advantage. There is another myth that small guilds don't want to add members because it hurts small guilds to do so.
This shows just how untrue that is. The math was designed in such a way that adding a person was always favorable. Adding 1 person for a 6 person guild is the equivalent of adding nearly 3 people even with the reduction in bonus. The sytem was designed this way intentionally. The reason there are a large number of guilds with 6 isn't because guilds want to get smaller, it is because the guilds below 6 want to get bigger to get 6. Any guild with less than 6 already has a big disadvantage and as many pointed out getting to 6 helps the members earn more even if some of the accounts are bank accounts.
This not unlike many of the free to play folks I know that have multiple accounts to get around the 2 character limit. This is in fact one of things that was hurting large guilds under the old system. 1 person earning renown but getting decay for 6 because they had 6 accounts in the guild.
Here is the reason for small guild bonus. Level is tied to rewards and DDO didn't want to exclude a large percentage of the customer base that prefers small guilds:
Paiz: "That’s definitely something that we’re still trying to figure out and balance. There is some help for smaller guilds in this system… we don’t want to exclude a guild that might only include four people. We think that’s a totally valid way to play, and we’re trying not to force people to have 50 player guilds. If you’re in a small guild, you’ll get a small boost every time you pick up, what I call, a “renown token” because we want to make sure those guilds are able to get their airships and things like that. "
The new system clearly isn't consistent with this vision as many from guilds of all sizes have pointed out. So we would like Turbine to explain if they are changing this vision and why. Many of us have spent years leveling our small guilds - always taking renown as an end reward, taking guild elxirs and playing by the rules. With the new system guilds with the same average activity level as us will get to get bigger airship and more amenities. We will not for only one reason - the high decay that is only a significant factor for small guilds. Although guilds of 10 and less are impacted the most, even most guilds in the 11-30 range will hit a ceiling at some point and be unable to advance. They are currently moving, but as they approach the new ceiling their prrogress will slow.
As for the small guilds on the leader boards are trying to slow down - what is the point? They at such a high level because they play so much. There is no point to punish over 99% of the small guilds because some are successful. I am happy and impressed with those guilds. Even when the large guilds get to 100 it doesn't take away the fact that those guilds were so good they could get to 100 with such high decay. That is not the case with other small guilds.