I wholeheartedly agree with the general sentiment of this topic.
As I am more frequently among the stronger 50% of spectators, let me share my perspective.
I like to explain and comment especially if there is an audience and the game is interesting or surprising. When someone asks a question, like “why did black move there?”, I often try to answer it.
On the other hand, if the game is very one-sided or decided early by a blunder, I tend to keep silent. You cannot really criticise the player who is behind for playing crazy after that. The same goes for other situations in which the conversation revolves around criticising the player instead of the game.
The big hurdle is getting the conversation started. When there is something comment-worthy, like a move that surprises me and is not an obvious blunder, I might do that. Also if I like someone’s style. The only suggestion that I have is that if you want to have talk about the game, you should do it yourself.
I used to be too shy to ask stupid questions in the company of much stronger players on KGS. “Why doesn’t white capture that stone?” - “It’s just one small insignificant stone, DUH!” - enough embarrassment for one day.
But really, if you have a question, ask away. You don’t have to “keep quiet” and “leave room” for the stronger spectators to discuss important stuff. It would not occur to someone who is 5-10 stones above your level to just go ahead and explain some moves that seem weird to you on his own initiative. The moves are simply natural at a higher level.
I’m not as afraid to do that nowadays. I might misread a semeai and say “white is dead”. All the weaker players will just believe it. It might turn out that I was just wrong. Who cares? At least I shared my thoughts!
Sometimes I try to count before the end of the game and say “W+3.5!”. I usually get no reply. Then it ends with B+12.5. shrug