In short: post more. Although I fully agree, I think there is a bit of a catch 22 we need to break through though.
I agree that there is a lack of engagement among the users here. This is probably the result of high-quality posts being drowned out by spam, and a lack of moderation has led to a sense of apathy. The up (and downvotes, for as long as they lasted) were a way to self-moderate, but they were gamed by the spammers, leading to further disengagement by actual users. So, I don't think just telling people to post more will take away this feeling.
In short: post more. Although I fully agree, I think there is a bit of a catch 22 we need to break through though.
I agree that there is a lack of engagement among the users here. This is probably the result of high-quality posts being drowned out by spam, and a lack of moderation has led to a sense of apathy. The up (and downvotes, for as long as they lasted) were a way to self-moderate, but they were gamed by the spammers, leading to further disengagement by actual users. So, I don't think just telling people to post more will take away this feeling.