It's not so much that I think writers never do anything by accident (good or bad or just weird or interesting) as I think that, if you're going to claim that something wasn't on purpose, you should provide support for that thesis just like you should support any other argument you're making about a text. I don't think that, for example, "Bioware is too stupid to have been exploring that theme on purpose," is a good enough argument. First of all, "Bioware" didn't write anything, individual people working for Bioware with a general common goal of creating a game but different styles and influences and life experiences did, and I think that matters when you're talking about intent. Maybe a writer made a specific statement about their influences when writing a character or plotline. Or maybe a theme in a story seems in conflict with other themes in the story (the tone of Return to Ostager vs. the tone of the rest of Dragon Age: Origins with regard to the nobility and royal blood comes to mind for me) and you want to consider why that might be. Maybe it's because the narrative comes across in a way the writers didn't intend. Maybe it's because different parts of the game were written by different people with different ideas about the themes they were exploring in a game that didn't really have a cohesive worldbuilding vision across all departments (which Origins notoriously did not, as David Gaider has discussed before). In some cases, maybe there's an intentional dissonance that itself brings up another theme. There could be a lot of reasons, and that in itself can be interesting to discuss, and I don't think we have to go into discussions assuming that writers never fumble the ball. I just think we should have better reasons for claims about authorial intent than "writers too stupid."