Conversations being split can be a feature; I know vaguely what to assume when writing for the audience here, but not at random other sites to which my comment could be syndicated without my knowledge.
And if that other audience responds there, I may not know, and if that other audience arrives here, the quality differential you've observed may evaporate.
A tech blog did this with HN comments at one point and I registered my strong objections in that thread: