First of all, the main reason is because of all the lies the government has told us from the beginning, for instance the 1947 UFO crash in Roswell. It's said that the government broke a lot of laws back then to cover up the UFO crash. After seeing the governments stance on the Roswell crash, you can't expect any type of disclosure for even today.
Personally I think the average person isn't ready. Bassett may be, but the overall human race isn't. I've talked to some of my own siblings and friends, most don't even acknowledge a conversation about the UFO/alien topic. It's so taboo and stupid to them, they feel they are way above it, which is kind of sad.
I did notice Stephen Bassett can be a little twitchy and nervous as times, it seems as though the alien disclosure topic has really got the best of him. I don't want to say it's turned him into a nervous wreck, because he's a well mannered individual, but personally I know how a loss of answers can make any person stressed out.
In this article I really don't want to discourage Stephen Bassett from doing his job if he ever reads this, but I just hope he understands more of the government's situation on the alien disclosure topic. Sometimes the truth can be too frightful and painful for the public to handle. I wish Stephen Bassett well and hope to hear more about him on the news and on Coast to Coast AM.