I didn't see it when I was in, because that was all I knew. But after leaving the org and attending other churches, it became clear to me that there is very little real spirituality in the WT.
JWs measure their spiritual life by how well they are living up to WT ideals and how enthusiastic they are about doing so. Those who have an authentic spirituality have it in spite of the WT, not because of it. And what they have is extremely limited. I really had no idea of the possibilities until I left.
A cult will never allow their followers to pursue an authentic spiritual path because they are too busy using them for all they can get out of them. They don't trust their followers to take that journey, and if they did, it would be a matter of time before they left the cult anyway.