Do you believe it is fraudulent for a person who does not believe in Spirituality to sell it?
No. But do I think Tim does not believe in spirituality? No. But I can see why you think he doesn't. I haven't read his books for years. All I know of him now is his appearances on Skeptiko. I have not been impressed, because I think he tries to solve problems that exist only in his imagination. I also think he is searching for something on a personal level - and this brings me to an issue I have with professional authors.They publish stuff they shouldn't and their publishers do not give a damn, because they make money so long as the author has marketable credibility.
Tim's apparent materialistic spirituality is essentially no different than Christianity's evolution into a theological construct which closed out 90% of human spirituality. It was trying to manage a diverse body of 'faithful' who retained connections with traditional ways - or at least made those links unappealing to more respectable believers. It was, finally, a failed strategy.
Tim isn't a theologian, and I don't find his arguments convincing. But evidently others do.
So let me reframe your question: Do I think that people who put a personal spin on spirituality should sell their version of it? No. Absolutely not. That is why I am not at all happy with the business of flogging books on spirituality and religion when they are written by people whose primary motive is to publish. It shouldn't be a business. The moment it becomes that there is a conflict of interest that is almost never disclosed. That does not mean I do not think that books on spirituality and religion should not be published. We need them - but as acts of service only. However it is a worthy endeavour to publish competently conducted research as a business proposition. What I am concerned about is opinion - as a theory or an interpretation.
I think opinion is important. I write my blog and participate in this forum. I have no interest in publishing for commercial gain. My opinion is coloured by these values. In Tim's case I think his problematic ideas arise from his role as a commercial author. I say this because I am aware that some thinkers incubate their deep ideas for a decade or longer - and my take on his theories is that they still have the umbilical cord attached. Some will say I am harsh and unkind in my assessment. But its my opinion - gratis.
A problem with being a professional author is that not a lot of people get to look at your argument before it gets published. Academics tend to be more cautious, often because their intended audience is fellow academics. I have been reading books on spirituality and religion for over 40 years, and I think I have developed a decent sense for the
spirit of a text. There are only a few authors whose subsequent works attract me now. Tim isn't one.