This is a sad state of affairs in Steem blockchain.

Ask.Steem is based on AskReddit model. In AskReddit even without incentives, which they introduced only recently, they chalked up about 30milion members. Asking open-ended questions appeals to the educated and probably the well-to-do class who take pleasure in intellectual pursuits regardless of rewards. Reddit has over 430 million active users. With that kind of user base, it is no surprise that they can attract 30 million users on AskReddit. The http://stateofthedapps.com website doesn't even give the active user number for steem but for hive the active users today is 13k. Therefore, we can safely presume that the number of active users on steem cannot be more than 20k. That is an abysmal number compared to 430 million for Reddit.

Another reason is that Steem communities tend to have a clique system supporting only their regular contributors and ignoring others even if they have posted good content. For an example, look at this post by @crypto.insurance in project.hope community. It received no support at all from the community (only 6 votes from non project-hope regulars) even though it has been two days. The same post in leofinance community received very good support immediately even though it was the first time @crypto.insurance posted on both the platforms. I would call the clique system "community circle jerking," a form of circle jerking. Besides, @crypto.insurance, I have observed others with good content suffering the same fate in project.hope community. I am sure it also happens in many other communities. Another friend of mine (name withheld) has just turned off his support for ph-fund trail, after learning of this practice.

Because Steem is based on incentives, it naturally attracted users seeking financial incentives. Therefore, except for a rare few, most of them tend to go where there are good incentives. And so, you got it right - financial incentives is one of the main reasons. If the founders of Ask.Steem community have SP of a million, then you will definitely see the community thriving.

Anyway, we cannot expect much from a user base of less than 20k. As the user base increases, Ask.Steem community would certainly do well. Meanwhile, you can express your support for Ask.Steem Community by following their trail either on https://worldofxpilar.com or https://steem-fanbase.com.

Personally I prefer Ask.Steem Community over AskTheHive community because I see the questions here are better, even though Ask.Steem Cummunity has lesser number of users than AskTheHive Community.