Well, that I'll have to be *this* person ...
- Most people here know very well that this is Early Access. This fact does not render any critism invalid in the slightest of ways. The majority of criticism expressed around here is implicitly of the form "I am bothered by [insert a player's problem here]. Please change this at some point (before release), in order to make the game better".
- The game has been in EA for over a year now. This simple, basic, fundamental problem with the equipment UI design has been there from the start. Since then, every other patch has brought improvements to the absolutely horrendous graphics that everyone is complaining about (just kidding). We've also had new character design options (like scales or piercing) that probably took half a day to implement. As well as the "addition" (revision) of the throwing mechanics. But we still haven't had a progress on the weapon slots.
- Larian's communication policy of "do not engage with the players' community, no matter what" means that we do not know if a) this criticism has even been registered by Larian, b) they have their reasons to want to keep weapon slots as they are, c) they are working on changing this. As a result, this criticism naturally keeps coming up. (This thread is far from the first time this issue is raised).
Now, as you said, you agree that the "Melee Weapon Slot/Range Weapon Slot" design is a problem. A problem so obvious, in fact, that Larian will surely understand that it is a problem. And fundamentally, you simply have faith that they just haven't gone around to fixing this.
Given the long list of similarly obvious problems, given the moderate time it would take to solve some of these problem (compared to the bigger time other changes must have taken), and given the long time these obvious have gone un-adressed (either in words, when Larian deigns communicating, or in actual changes, when new patchs come out), some people don't have the same level of faith as you. I'm one of those.
So I am, hm ... happy, in some "well, that's apparently the best I can expect" kinf of way, that other people keep bringing up this issue.
