No reason to engage. I think "discussing" a topic with another "online persona" is almost always a waste of time. I also find most comments to be speculative, argumentative, uninformed opinions, trolling, jokes or trash. It is great finding a decent comment chain, but usually I'm late to the show(like now)!
When I was young I enjoyed commenting and voicing my opinion, after 25 years online, I no longer derive satisfaction from it.