Here are few examples of questions which are on-topic, but downvoted:
How many alien races are on Earth according to the Canada's former minister of National Defence (based on his interview)?
This is a valid question, as Paul Hellyer talks about alien technology and races in public. It is a fact.
If ghosts exist, and can alter anything they would need to expend some energy how could that energy be replenished?
The propose of the site is to answer the questions like that, whether you're believing in ghosts or not. There are many paranormal investigators which can answer such questions.
In my opinion these questions are valid for the proposal, but it seems downvoters weren't keen on commenting, so author of questions don't know what to improve. Secondly these are only sample questions which may or may not appear on the site, they don't have to be perfect. The questions doesn't have to be judged whether they're answerable or not. The goal of sample questions is to demonstrate the scope of the site.
So why people would still downvote without any comment and how to avoid that? Any suggestions?