That's right. Collect everything, everywhere, forever.
One of the pillars of the Diablo franchise are the items. We all had mules for storing runes, gems and other stuff. And even with 5 mules, all full with items, you sometimes had to get rid of something against your will.
Is it really necessary to have a limited inventory size? It's not like the chars in Diablo get any slower when their inventory is full, right?
I guess the inventorysize is already decided for months now and beyond negotiation, but it's just that I can't see why limiting my inventory is more fun than having a bottomless bag.