The saying is absolutely true...demonstrably so in fact.
Melee weapons are outdated.
But as I said before...
Barriers, Shields, and things like Biotic Charge and Turian's Havoc Strike alter the framework of those otherwise normal circumstances.
Also just as an fyi, never once have I used the words "Rule of Cool" to defend melee. I want plausibility. The thing is, melee weapons in the ME:U are entirely plausible given the technology available at the time. And more than plausible, they are already in the game, often and loudly.
To be fair I don't want katanas and space ninjas either. I want brutal fast paced melee action.
...the funny thing?
I already have that in MP. It just needs some work and tuning, and expansion.
If rounds fired at supersonic speeds by mass accelerators can't pierce armor than some guy swinging an old-timey sword isn't going to have better luck. The former is going to have a much better change of penetrating armor.
See, that's not necessarily true. And the flaw is that you're presuming I'm talking about an "old-timey sword". As I mentioned earlier, a 1.5m long biotic sword that may as well be a tethered singularity, or a mono-omniblade wielded by a cybernetically enhanced creature would do the same or more damage. You can house a lot more damage capable options in something the size of a sword or a mace than in a bullet...
What I find stupid about the saying isn't that it doesn't make sense, it's that it puts every single person who says it in a tiny box they can't seem to get out of in a game that's by it's definition, imaginative. 30 times later it just makes me lol.
Again, if you're going to hit up real world parallels, then you're missing the times that defense has trumped offense. Plate mail at it's beginning was virtually impossible to eliminate, that's why everyone started using it. Offense had to keep up, and it did, but there's a lag behind it. Similarly with Ironclads. They were nigh invincible for a while.
In the ME:U, they are at the point where a lag like that is entirely plausible, feasible, and already placed in the game.
The simple matter is, if you play the game's MP side of things melee is an entirely viable field to work in. And we're talking about that game.
Vorcha Light Melee works amazing well on lower levels and is a tonne of fun. Krolords work on all levels if you know how to play em. Turian Havocs have Havoc Charge, a completely melee based option to close with your enemy. (Albeit I find havocs a bit suicidal) Batarians have Blade Armour to repel melee. Cerberus Dragoons and their enlightened cousins the Pheonix Adept/Vanguard have Smash, a biotic ability that is melee ranged and does a trucktonne of damage. They are also equipped with what I would term "Rule of Cool" electrowhipthingamadeelies.
Melee can be a primary weapon for many kits and do just fine, but it needs work on it. Even then I'd want a pistol or sidearm to accompany me. Range is necessary under many circumstances, but melee really isn't far fetched. Even as a plausible primary option.