So the question is what counts as authentic spirituality. I don't like the word "spiritual" because it comes with baggage. I prefer existential philosophy. After the New Age movement, lots of practices may be deemed "spiritual," such as the self-help movement, just as anything goes now as art. But those movements are often co-opted forms of consumerism.

It's almost just a semantic issue whether we call the kind of secular humanism you're talking about "spiritual."