People on this sub-reddit seem to have short memories. There was a whole development manifesto that went into the various performance improvements that GGG is making. It is naive to think they aren't working on improvements.

A year and a half ago, the biggest complaint was desync. Now you hardly ever see it mentioned. It wasn't perfect when it came out, and had various bugs that needed to be fixed, but you hardly ever see a post on desync on this sub now.

I expect the same will continue with load times. They are completely changing how they do loading. It's a big change, but necessary in the long run. There is still more to do in this area, and they've mentioned they are working on a new asset management system that can load assets asynchronously which is tentatively targeted for later this year.

One of the biggest limitations they face performance wise is the fact that they are still using a 32-bit client, which limits the amount of memory that can be addressed. We know they are targetting to release a 64-bit DirectX11 client sometime in 2017, rather than the 32-bit DirectX9 client we have now.