When I was young I asked a C.O "Why doesn't the Org do programmes for Television?" the reply I got was " because no matter how good the programme, a better one comes along and people then forget our message, it is better to speak to people person to person".
I think he must have been forearmed to answer this question, because shortly after , if memory serves, the Org had something similar in Print.
But the argument in that answer still stands I think. Their Videos etc are not in fact good enough to compare with others, but they may make some that just about are, but then if even mildly successful, they will be copied and improved upon by commercial interests that are non-JW, and become redundant.
Also if someone was moved to think about maybe joining the JW's, the hoops they would have to go through to get someone to call on them would be off-putting to most, go to a very Culty Web Site and request a Bible Study ? how many will actually do that ?