Bioware character only stand out if you expect some kind of emotional attachment to them, romance them and so forth. That is not the only thing that makes a character interesting though. In terms of depth and complexity the average Bioware character i know (only ME) isn't really special.
And there is humor for example. Biowares "funny" character are usually an epic fail if you ask me (Joker). Bethesda has lots of hilarious people (Harold, DJ Travis ....).
I think that is missing the point...
I agree that not all characters written by BioWare are created equal, but I also believe that BioWare has the market cornered when it comes to making them both interesting and engaging, outside of romancing them.
We can name a lot of traits with characters in BioWare games; partially because some of them have several games to grow as characters, partially because of their dynamics and backstories. The wide range of ideals and beliefs, hooks and information they gave is both expository and with a purpose of deepening their characterization, and the voice actors now a days have excellent direction to give them actual life, even with a lighter script or a weaker characterization.
Yes, part of it is expecting an emotional attachment, but why do they keep giving us squad-mates and companions if they didn't expect you to attach to them in the first place? Willingly not attaching to them is a personal choice, but not a universal design philosophy; it's why they spend so much time with writing, banter, characterization and blocking with them now a days I bet it takes up 1/4 of a games budget just for companions at this point.
Bethesda gets credit for making good characters, Three Dog and Travis are good examples of that, but Fallout 4 is the first game where they had good companions, even though only like 4 of them shine, and the other 8 are a bit half-baked. Hell, one is a dog and it expresses more than your Mabari hound ever could. Got to love game-engines for that though...
I guess the point is, BioWare has set the standard after all these years, and companies are trying to catch up to that still. That should at least be undeniable.