Dunno about you but I believe most of the threads that ended up locked have fallen under one of these three:
- People went off topic and it the focus of the conversation became personal and occasionally aggressive discourse, or one specific person kept trying to drive the conversation off topic and engaged in an offensive manner in the process
- Someone or several people insisted on making the conversation objectively unpleasant for everyone. On topic or not, offensive and agressive behaviour is a great way to kill any productive conversation.
- Someone, or several people, started saying things that were homophobic, racist, sexist or transphobic. Hate speech isn't even legal guys lol of course tapas doesn't want people to slide down that path anywhere near their brand.
As for established creators being too busy to contribute much to threads... yeah that's pretty true. Usually the most successful people spend more time doing the thing rather than talking about the thing, unless they are public speakers. And when we get off work we would rather spend time with friends and family. It's just natural.
If we provide our knowledge in a discussion that's an act of kindness, and one we won't always have energy for. Especially not considering sometimes our help is met with frustration or anger. Most of the time people appreciate our input, but there's always people who get angry with the truth and take it out on the messenger.
I usually judge on a case by case basis whether or not it's worth the effort. High effort with low chance of anyone taking it to heart? Nah mate. Low effort with high chance of the person listening? Sure, why not. This is why straightforward and simple questions on the forums more often get answered.
Anything inbetween those extremes is a grey area and will depend on what mood I am in, and I can only assume the applies for many others who work with comics professionally.