Hello Gravity.
I can quite understand your sentiments on this one but it might be a bit trickier than assuming these people haven't been on the site for years.
Judging by the number of 'views' on blogs, compared to the numbers of written contributers, there are obviously far more people who watch, read, observe and don't reply than those who do. On a very personal basis, I value their passive contributions highly and it gives me great delight when one of them will share with me that they enjoy my writing. In these cases, I usually look up their profiles as I like to know a little bit about the people who correspond. Sometimes, these are possibly the people to whom you are referring, as their profiles indicate how often (or not) they have posted. However, in order to follow my rhyming verses, they presumably come on here regularly, even if there is no way of knowing whether it is the same people other than them implying that they have read many more blogs than the one they are commenting on.
When they do reply in this way, I envisage and hope that they may be speaking for the majority who prefer to stay silent, yet still appreciate the active correspondence that goes on between those of us who are willing to document our thoughts and feelings.
I would not like to think that people who only come on here to observe are thought to be any less important than those who actively participate. Would that not be equivalent to thinking that the spectators and supporters iare not important in other activities?
Best wishes
Bill