That all makes sense, but I don't see how it supports your uncharitable read of the original comment. Both because they could very easily have meant something a bit different (we have no idea how old the kids are or whether they were even around all weekend; maybe there were times when they were at friends' houses or similar), and because vibe coding could be the interruptible activity they do while the kids are busy. Maybe you feel strongly that it's not a legitimate use of that kind of semi-downtime, but we don't know if that's what they were talking about in the first place.
"Hours spent on the project" would be a much more useful metric, with no confounding variables. As it is, the mere mention of interleaving time with your kids and time engrossed in tech hits a nerve at time when IMO too many parents are doing this already, and lends unwarranted validity to the idea.