First off, on simplicity... IMO, you can make a 1st-level character for any edition, core books only, without a computer, in 15 minutes, assuming you're familiar with the system.
It's a false metric; the real key is what happens when you move beyond core and beyond 1st level. In 3.x, I needed Heroforge. In 4e, I pretty much depend on the character builder. But again - this is because of expansion, not because of the innate complexity of the system. On the other side of the coin, when my group of 1e newbies made their characters, it took us a few hours because they didn't know the system.
On weapon proficiencies in 1e/2e, I agree with delericho that they add absolutely nothing, other than bookkeeping. I'll go further and opine that when they do make a difference, the difference sucks; I want my fighters to be able to use that shiny, new scimitar of speed right away. In my 1e game, I did away with them... If a fighter (or fighter subclass) wants to specialize, they need to give up training in a loose group of weapons. I have further restrictions, mind you, and I've customized it a bit - but that's largely it.
-O