Because common items are basically just garbage that's going into the "sell at first sight" pile.
Well yeah, that is the whole point of being to distinguish between rare and common items. I.e. You can easily spot common items, which you of course throw onto the junk pile and sell later.
You have to switch between multiple screens of items if we're talking about a grid. The sheer volume of loot you get - if we're talking about a game like BG1-2 or NWN1-2 - means multiple screens of loot. Assuming you even class the screens by item type, that still leaves you with a huge clutter of items.
Not necessarily. Pillars of Eternity (i'm sure you've heard of it) will have separate inventories for all party members (6 in total), but all of it will be shown on one screen, which should be about 100 slots total. So yeah, you can easily fit the entire NWN2 or Baldur's Gate inventory on one screen, just because it wasn't done in those games doesn't mean that it is impossible. BTW, the inventory will of course be be slot based in PoE, because that is what the fans want.
Anyway, I don't see how a few inventory tabs could be just as bad as the numerous categories that a list based inventory has - at least you don't have to constantly scroll back and forth through your inventory.
And even if you have a "junk" screen for items that you're going to sell right away you still have to take the time to actually organize your items each you get a new one and put it into your junk pile. And when you get to that "critical" item that makes you go to another screen because you just filled out one screen of grids for a type of item, then it gets real nasty.
Even a list based inventory needs to be cleaned up every once in a while. You still have to manually throw the junk you don't want (anymore) onto the junk pile. With a slot/grid based inventory at least you don't have to constantly scroll back and forth to do so.
You're acting like we have 5 magic rights in a game, instead of 40.
With a grid based system I'm constantly moving between different screens were I've stuffed all of my armors, rings, weapons, whatever especially since weapons and armour take up bigger #s of grids so I have to play tetris to keep them all on the same screen. Then I'm hovering over each to see what the stats of each are... and all of a sudden there's no difference between this and a list other than the visual arrangement.
This is just as annoying as a list when I'm scrolling down to find stuff.
I am talking about 5 - 10 rings, because it is unlikely that you will have more than that in your inventory (junk excluded).
Anyway, switching between tabs in a grid based system would of course be just as fast as changing the category in a list based inventory. The grid based system would of course still be faster, simply beacuse you do not have to constantly scroll up and down through the inventory.
You seem to hate the inventory tabs that certain games with grid based inventories have, but like I said, the entire party's inventory can be on one screen. PoE will have this feature.
BTW, I don't like Diablo style inventory tetris either, a slot based solution is much better.
And what if I don't want to create a special set of equipment with special bonuses? What if I just want to use one item out of that set? Not to mention that in a grid, all of these items would take up different space, so I'd have to play inventory tetris to fit these together on one side.
Then just equip one of the items.
And I am not a fan of Diablo style grid inventories either, because I don't like to play inventory tetris. I like slot based inventories, like in BG, NWN2, etc.