The flashy complaints seem misplaced, because it's not like the isometric combat wasn't designed to be flashy and visually impressive for its time.
At most it can be a complaint aimed at the animations, but once we get into verisimilitude arguments there are way more serious issues with the very idea of 3D and traditional RPGs than flashiness.
There's a real complaint here about combat mechanic and gameplay, but the aesthetic point is silly, because it's nothing more than an aesthetic point.
Well, language is not something explicitly exactly defined and not something to exactly define. Language always also carries information about how it is to be interpreted, alongside the message/idea. Language always relies on its own context. Language is a tool to transfer an idea, that is inside our head, to other people's heads. If the involved persons are well tuned to each other this works quite well. And if a group of people use language between themselves they will eventually become well tuned, better and better.
Personally, I seem to understand very well what Jen-Yu is trying to say. I think he puts it quite succinctly. "Flashy crap". And I agree. The DA:I combat is some of the worst gaming content I've ever experienced. And the aesthetic point is not silly. Aesthetics is not something that floats around irrelevantly in some vacuum. It totally represents what the developers were thinking they had to have combat convey. (I strongly suspect that it's even mostly that, i.e. the combat is primarily built to accommodate the aesthetics, rather than the other way around.)
I think it works well for EA's marketing people though. This fiasco is probably what they have worked hard for ever since they made the Sacred Ashes video for DA:O, (though, of course, the action is still "slow and shuffling" in that video, compared to DA2 & DA:I). That's my impression, that the combat has been created more to satisfy what has been told is required, than any personal, genuine understanding of why it would be interesting to play.
As for these comments regarding comparisons what other games have done, they are really what is truly irrelevant in this discussion, rather than any kind of appropriate argument. I do certainly agree that combat in, for instance, BG2, was "flashy", if that was your meaning? But "flashy" in a different context. In different art works, in a different atmosphere, in different circumstances as to what the game feeds back and what takes place in the player's head. The exact meaning of the word "flashy" relies on the context. It doesn't have to imply that it's insulting or offensive.
But is it "constructive criticism"? Well, yes, I think it is, sort of. It expresses a discord, between what the gamer wants DA to be, in terms of mood and atmosphere, and the zip-zap-Kaboom-hotrod-samurai-cartoonish, "fun", "flashy crap" that EA wants. Since opinions vary greatly, it might be hard to understand or make anything of. I respect that. But I genuinely suspect EA marketing is very, very wrong about this. The new direction of DA2 and DA:I is obsolete. The future is a more serious tone, and intuitively understood as more "realistic", like for instance The Witcher (and DA:O, to some extent) represents. That's what I believe.
I do not want to say that the flashiness is what is wrong with DA:I combat, however. Rather, I'm suggesting it's the cause.
As to what is wrong with DA:I combat mechanics, I can express my own opinion: There is nothing interesting going on. Normally, my purpose of combat in an RPG would be to represent a threat, obstacle, challenge, dread, that the character must find means to overcome. Beyond that I typically do not have any interest in the combat. It's not like when I play a FPS, strategy games or a game like UFO: Enemy Unknown (the original, ofc), where it's very much the main reason for playing the game.
In DA:I it's not working. Theoretically, I could have played it micro-managing Tac-Cam style. But it's not working out, because when you can only take a few meters walk and then all the enemies will have been respawned yet again, it gets tiring and pointless to very silly proportions. It wouldn't have worked so well anyway, since the PC UI was so painful. My solution eventually evolved into playing ranged character (archer rogue). And that in turn eventually evolved into "F* this!-lower difficulty-and just hold down <R>" and yawn until the screen has stopped flashing. So somewhere there the combat ceased to have any purpose for me. It's no longer any dread or obstacle.
I do appreciate very much though, that the combat can be played 'easy & hold down <R>'. Otherwise DA:I would be pretty intolerable for me. As it is I can enjoy the game for so many other reasons. I focus on that.