I found that I gradually became less annoyed with the need to carry extra crafting-stuff in my inventory over time - mainly because, as I got used to the dungeon economy, I had a better sense of which items were actually valuable and which I could safely pitch. But I don't think "users eventually become numb to the pain!" is a good justification for all the inventory-fiddling that sometimes becomes necessary. Plus, you won't really know which items are useful to keep around unless you've read spoilers for all of the crafting recipes.
When I switch from a build that does crafting to a build that has none, I always notice a dramatic speed boost - "Hey, I've only been playing a short time and I'm already at Dlvl 4! ...Right, because I don't have to poke my inventory to rearrange crafting materials all the time."