I was giving my opinion here, like anyone else. It seems I got your attention. I wonder why... 
Do you deny the superiority of Bioware's writing? As TommyServo said, my Skyrim game was also full of ported witcher meshes -armors and hairstyles, mostly- because the design is really good and that's a point for CDPR. Writing is not their strongest trait, that's Bioware's game.
Is it really up for debate? One could say "I like 50 shades of grey more than Shakespeare" but that doesn't change the fact that Shakespeare IS and WILL BE eternally superior to 50 shades... because there ARE quality standards.
Look I like many trashy things, like smutty fanfics, yes. I do looooove my smutty fics. The thing is that I realize they are objectively TRASH and I don't try to deny it. I don't take any offense either because reading smutty fics doesn't make ME trash.
So don't get offended when I say Bioware's writing is vastly superior. Period.
I am not offended
, but I disagree.
The writing on both games is pretty much equivalent most of the time.
Bioware has better voice actors all around and so, better delivery all around, and they are good at funny and at character fidelity. The Bioware villains can be pretty goofy and sometimes they wonder into exposition territory for a long time, and it is a bit boring (like the SPOILER ALERT scene in the fade in DAI when the "thing" keeps beating around the bushes and being vague).
The Witcher 1 is inferior all around (but not 50 shades to shakespeare inferior) but two and three are pretty good. The dialogue in The Witcher is more grounded and I can see one finding it less interesting, but it has its moments of genius, like the Foltest Siege in TW2. TW3 also do not have companions of note and does not have goofy characters like Iron Bull and Sera, but CD Project is very good in writing dubious characters, like the captain of the guard in TW3 (and Vernon Roche in TW2) , that can be nice and a dick without leaving characterization.
In any case, at no point during The Witcher series the dialogue and plot goes all ****** up like in Mass Effect 3 - in the beginning with Shepard's caricature speech and in the end, with the Deux Ex Machina. The ending of DA2 is also very contrived plot-wise and it led to some nonsensical dialogue as well.
I would say that generally, Bioware has wit and flow and CD project has consistency and focus. Both styles backfire at times, with Bioware going crazy and CDP going uninteresting.
I can see a person preferring one style over the other, or liking both for what they are. But, technically, I do not think it is possible to say one is vastly superior than the other. You are welcome to prove me wrong, though.