Welcome Silvia,
You make a great point. I have been in your shoes many, many times, even in my own house while hosting 20 or 30 JW's. It didn't bother me much, until I discovered that the leaders are full of it and they know it. Not only that, they are willing to use their BS to manipulate, control, enslave, and ultimately ruin many a life.
The internet is their biggest problem. Another problem is the training that JW's get. It's mechanical, staged, no passion, no conviction, no zeal. I don't blame them, too much BS and cult tactics prevent the production of great preachers.