The constant chase of new features is an inherent problem with software in general, not just online games. Let's face it, bug fixes don't attract new customers. That's not an excuse, nor does it absolve the developers, it's just an acknowledgement of the inherent business drivers a company can't escape or ignore.
GvG is a particular issue for Inno right now since it doesn't run on mobile. An ever increasing majority of the player base can't even access it. Like it or not, GvG is on life support and it's only a matter of time before Inno declares some new feature to be the 'replacement' for GvG. Think DC and Treasure Hunt. They never could, or never would port Treasure Hunt to mobile, so after DC gained enough traction, they declared DC the 'replacement' and removed Treasure Hunt from the game.
I'm not sure what Inno will introduce that will become the 'replacement' for GvG, but one thing I don't see is any more investment than is necessary to keep GvG limping along until then. Trying to lobby for Inno to invest into truly fixing GvG, to me, is just ignoring reality. Enjoy GvG while you can, but I think it's days are numbered.