For a TL:DR (and particularly if you are an ArenaNet dev) see the bottom of the post.
The Guild Wars 2 gem store has always allowed players to convert their in game gold into "gems" which they can use to buy items from the gem store.
This system has worked in tandem with the ability to buy gems with real money.
Before this latest update players could choose the amount of gold they wished to spend to buy items.
Need a key for 125 gems? Then buy 125 gems! Need an outfit for 700 gems? You guessed it, buy 700 gems!
The new system works like this:
Need a key for 125 gems? Buy 400 gems and have 275 left over! Need an outfit for 700 gems? Buy 800 gems and have 100 left over! Because reasons!
Players can now only convert their in game gold to gems in increments of 400. Once again ArenaNet's justification for this change has been: new players found it confusing and as veteran players we wouldn't understand.
This is an argument they've used before, and I've written about here.
As one eloquent redditor quite rightly put it: "Bullshit". First off, if the interface is confusing players - then change the fucking interface. This has nothing to do with the ability to convert however much gold you need. The interface is just the way the player interacts with the system, not the system itself.
Second, which "new player" has the gold stashed away to be able to convert gold into 400 gems anyway!? At the current conversion rate that equals 75 gold! I played for a good 6 or 7 months before I had that kind of currency lying around, and even then I wouldn't have thought of converting all my worldly possessions into gems to buy a cheap looking outfit! There is nothing about this update to this system which is helpful to new players, in fact it isn't even a system which new players will have the option to use because they simply will not have the gold to buy the required 400 gems.
I'm afraid the actual motivations for this change are very thinly veiled. Before you might convert a small amount of gold into gems to buy a Black Lion Chest Key from the store, now you are far less likely to have the spare change required - so instead you BUY the gems with real money. That's the reason this change has been made - the only thing confusing is why ArenaNet are so brazen about it. It is mind boggling.
So, just to spell it out for ArenaNet - feed this back to your team:
There is absolutely no way that a new player will have the in game gold to buy 400 gems, so they will spend real money instead. This is NOT a system which is friendly for new players, it is absolutely the opposite. This is a system to rinse more real money out of new players. You. are. fucking. it. up.
Kotaku (I know, ew, but bear with me) are claiming that ArenaNet will be reversing the changes to the gem system in light of our "ranting". They don't actually give any source for this announcement but I anticipate a statement from ANet soon if its true. The system works. Rant for justice. All haile the rant.