You can't always auto everything on GvG either.
Aye this can be seen on the All Ages map (AA) in particular and especially since the release of Oceanic Future (OF). AA is a map that demands a high attack bonus and even with a very high attack bonus, on the AA map a player is faced with several defeats per sector. Thus, GvG players are faced with a drive to increase the level of attack they can obtain either through GB levelling or obtaining special buildings. Which oftentimes sees GvGers buy diamonds to buy more of the special buildings in events (as Hossam has expressed already).
The very diverse nature of the troops on AA creates a need for an excessively high attack bonus, a well leveled Alcatraz and a lot of team work (which means higher number of players, because a few players alone will be crippled within days) if in a guild that wants to compete to any great level there. It's an ever changing environment and players need to keep progressing to keep up in real time. Thus, GvG drives a need for GvGers to progress.... and even non GvGers want to keep up with their GvG guild mates ... thus it drives their progress. Impatience, frustration or a sheer want to participate at the same level as everyone else, can see the buying of diamonds. That's just one aspect of course.
While I'm sure there are many other reasons why people spend diamonds, I personally only ever see members spend on diamonds when they have a need to meet a certain level to participate effectively in GvG and are unable to compete with the rest of us in the guild/outside it.
I'd like to add, on a personal note, I'm an avid GvGer, it's the only aspect of the game for me, while I respect others find differing ways to enjoy the game outside of GvG .... I see everything in the game as a mere extension of GvG. So in my view, GvG is at the heart of the game while everything else is an aspect that allows me to progress in GvG. The city is set up to allow progress in the game to be competitive on GvG and to grow GBs which are in turn there to assist my progress on GvG. Guild Expedition (while definitely has other purposes for many) for me it only links back to city progress for GvG and GvG power/level for the guild, so they can have more benefits that assist their GvG progress like troop reducement time and fps.
In a GvG guild every aspect of the game is utilised and driven to assist GvG Progress. So for the GvGer it's required to progress on many fronts, have bigger cities, have bigger GBs, have specific special buildings, etc etc. GvGers seem to have a lot more reason to progress at a faster pace than non GvGers (but that is just my opinion).
Further, GvGers may actaully spend more diamonds in this game, if we knew it would be worth it. With the game in the state it is and no word on whether or not it will be fixed, why would we spend money on diamonds(even if we want to)? And certainly that is the consensus behind why some stopped buying diamonds at one point.
For me it's not a question of the relevance of GvG but rather, what's the relevance of everything else for GvG lol
Unfortunately I do, GE is the biggest bore going, no pressure no skill and no effort
There's a small bit of skill required on the battle field, some of the battles are truly challenging, but aye there's only so much GE one can do before it becomes a monotonous task. GE can never compete with GvG because in reality you're against a computer and the competition between guilds is too passive, there is no direct attack/counter attack. Each week it's the same over and over, and after a while the incentives to play only end up being the same bunch of useless buildings we have way too much of anyway. In my opinion, GE has no stamina to survive longer term, it's of great benefit to progress the younger (not referring to age but game progress here) player… GvG on the otherhand, as Mithrander rightly points out, is ever changing, requires advanced planning and foresight. It also requires direct, heart racing, real time challenges, with real minds behind the opposition and in which there is a risk of loss, which makes winning, when it happens, more fun! It's also missing teamwork and socialisation, while it takes a team to win GE, it doesn't take that team coming together in the same space and time, this particular aspect of GvG plays a major role in adding to the excitement and enjoyment of the game. This is what we would miss, as GvGers, the most.
This is just misleadingly simplistic. Yes GvG does not really require diamonds. But for people who are most interested in GvG they'll be motivated to buy diamonds to get attack buildings at events for example, or SoKs so that they can level their attack GBs faster. If GvG dies out then those players are less likely to spend money for a quicker city development. I don't think that's very hard to understand.
"some players hardly make a difference" Regardless of how rude this statement is, and the fact that being few is not a reason to shy from expressing our opinion, but how do you really know that? The fraction of FoE players that are active in GvG is actually not the only relevant metric here (regardless of how many times you mention they're the minority). Do you have data on what fraction of diamond buyers are GvGers? Can you speculate the amount of potential loss if this aspect dies out? Based on what? There's also complicated indirect effects: GvGers tend to be leaders and more than average active members in top guilds (just how ranking works). If they become uninterested in the game then App players and non-GvGers in those guilds will have their gameplay affected too.
Nicely put