Remembering what items were in which slot before dying and making items return to that slot is sensible and something that I've supported for a long time.
The loot bag idea, while sounding good, would be (a) a lot of work to implement, since the entire contents of the inventory would have to be saved in a single item, which is a mechanic that simply doesn't exist currently, and (b) incredibly abusable for compact item storage – just take all the stuff you want to put into one bag and kill yourself at your base.
The other ideas people have made in this thread – that mediumcore characters only drop part of their inventory upon death – I am strongly against. If you think Mediumcore is too difficult, you might want to start keeping chests of backup equipment around your base. If you do it right, you're almost as strong after death as you were before. If that's still too much, play softcore. Mediumcore is all about the difficulty of making sure you can get your stuff back when you die – that's literally the only difference between Softcore and Mediumcore. Those of you comparing Mediumcore to Hardcore should maybe get a bit more experience with both, since (a) Mediumcore allows you to keep your character upgrades upon death and (b) Hardcore would require you to leave the world to get a new character, which deletes all that stuff you dropped.
If you want something that's like Mediumcore, but you only lose the stuff that wasn't important anyways, there could be a separate difficulty ("marginally-less-softcore"), but until then, why not play Softcore and drop all of that stuff manually when you die?
Honestly, my experiences with Mediumcore have been a lot of fun. If you plan ahead properly and have a bit of skill, a Mediumcore corpse run can be an adrenaline-filled few minutes of awesome.