Hardware limitations should only be an issue for things requiring raw horsepower. Graphics, huge numbers of things on the field at once. Those sorts of things. It might explain some underwhelming moments and non-destructible enemy ships (but weren't we able to blow enemy shit up in later Halos?) but I seriously doubt the hardware is stopping Destiny from implementing many of the more reasonable things that have been suggested - vault space, a more sensible reward structure for some activities, in-game LFG and clan tools, more variety in armor models, etc. It's not a hardware issue.