I can completely understand why some people balk at the idea of having melee attacks be a simple action. The primary argument usually used is that "it is a series of attacks and counterattacks" etc, which is how the book describes the action fluff wise. The problem there is that you/they/people are using a "fluff" argument to counter a "mechanics" argument. That argument is totally valid and 100% correct. The issue here is that the argument doesn't in any way actually counter the argument for melee being a simple action any more now that 5e has come out. Let me explain why.
Let us be clear: the arena we are arguing in is that of mechanics. We are debating whether or not melee attacks need to be a complex action or a simple action. We are not debating about how a melee action should be described to players in the course of a game. I think we can all agree that the description will vary from GM to GM, from game to game, from combat to combat, and from action to action. How to describe stuff happening is "fluff". What action we use is "mechanics". Regardless of which action is used, a GM is going to describe it however is appropriate for that particular combat situation.
In other words, a description can be altered simply by the way the GM or players choose to describe the action taking place. Just because an action is described a certain way in no way changes the in-game mechanics behind the action. Whether I describe it as a series of actions, or one straightforward action, you still have to roll the same dice and it's resisted the same way. So we need to instead view this fluff argument as a mechanical argument for any headway to be made in either direction for this debate. So, that being said...
The reason why melee attacks originally needed to be complex rather than simple was to prevent people from making more than one melee attack in a single combat round (without needing to split pools or whatever). This was due to the fact that you could only have 1 complex action in a round, but you could have 2 simple actions in a round. Firing a gun took only one simple action, but you could get 2 of those in a round. Yes, it makes logical sense that you should be able to shoot multiple bullets in the time that it took to be in a fist fight with someone (moving a finger vs throwing a punch), and it also makes logical sense that your "other" action should be far more limited if you're in the middle of melee combat vs. just pulling the trigger a single time; but that wasn't the real reason why this ruling was made. It was for mechanical game balance reasons. The description about it being a series of moves came after the fact as a means of explaining away the need for the mechanics.
Now, in 5e (as opposed to all previous versions) we have a new limitation: You can only make one attack action per combat pass. This is regardless of the "type" of action (Complex or Simple). This fundamentally changes the balance of the mechanics of the system. We no longer need to use action type as the inherent (and only) limiting factor for melee vs ranged. You can use the new "Multiple Attacks" Free action with either ranged or melee attacks.
In fact, there is no free action that you can combine with a ranged attack that you can't also combine with a melee attack (other than ejecting a clip I suppose). Furthermore: realistically speaking, there aren't any simple actions that a person in melee combat couldn't do just about as easily (or with as much difficulty) as a person firing a gun at people. For the purposes of determining what "other" (simple) actions could realistically be accomplished by a person in combat, melee and ranged attacks are effectively identical.
The argument then becomes basically about this:
For the purposes of game balance (and not descriptive reasons), should a person engaged in melee combat be prevented from doing the following actions?:
Activate Focus: This is a thought, so no.
Call/Command/Dismiss Spirit: Also a thought - no.
Change device mode: We have a free version for linked weapons, but so do guns, so to make things even - no.*
Observe in Detail: probably should be prevented from this, although I would argue that someone shooting should be also, so to make things even - no.*
Pick up/Put down object: drop object is a free, so presumably this is doing something more "gently", picking up things in the middle of melee though isn't impossible at all - no.
Ready Weapon: This is done often, and is not an attack like quick draw (or iajutsu), so - no.
Shift Perception: thought - no
Stand up: - often done, but debatable I suppose - I would rule no.
Take Aim: why would you? but this could be an interesting thing to combine with a melee attack. I like the concept, and don't see why not, so - no.
Take Cover: easy to do actually, assuming you're close enough to do it. Worst case scenario your attacker/defender comes with you. - no.*
Use Simple Device: if you can do it in the middle of a firefight, then I think you can while in melee. Realism is stretched equally for both melee and ranged in this case, so - no.*
*A number of these stretch the imagination as to how (or why) someone would do one of these things in melee combat, but the imagination is equally stretched as to how someone in the middle of a firefight would be able to do it as well.
The bottom line is this: There is nothing that would unbalancing (or any more unrealistic) about letting melee attacks be simple actions instead of complex actions given the new 5e limit of only being able to take one attack action per combat pass. So - There is no reason why we can't have melee actions described as a "series of" actions and (under the new 5e rules) be a simple action as well.
I personally feel that melee attacks should be a simple action without any additional penalties. Period.
However, given people's feelings about melee being a task that requires more concentration or whatever, I could see there being some sort of trade off where you would still keep "regular" melee attacks as complex actions, but get a simple version where you would get a penalty to either defense or attack dice pools (or both) when making a melee attack as a simple action.
