An OP certainly may attempt to “steer threads back on track” by expanding on and clarifying his or her OP, responding to relevant answers, asking follow-up questions, etc. Normally, people are pretty respectful of that. An OP doesn’t get to play junior mod just because he started a thread, however.
There was no threadshitting or hijacking, anyway. There were just a few side comments. And if you’re going to object to side comments, then you should refrain from making them yourself: