I don't know anything about the man or his success record, but as an academic he may not wish to be accused of conflict of interest by promoting companies where he has a personal financial stake.
The people who actually have the ability or to predict valuations/prices (better than the market) are busy making millions, if not billions, of dollars, and they most certainly aren't going to tell you about their predictions/models. If they do, it's after they've already invested or shorted the asset.
Academics identify a pattern that generates superior risk-adjusted returns and then publish their findings - this then leads to the anomaly disappearing as investors trade away the alpha. [0] The track record of an academic can therefore only be meaningfully discussed in terms of how well their model performs in back-testing. Saying they don't have a good track record misses this point.
Perhaps there are successful academic investors who achieve alpha and don't publish their research, however they wouldn't show up in any meta analysis.
[0] https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3054718
Perhaps because they enjoy academia far more than money making?
Some people like Grigori Perelman [0] are just not interested in money or fame, or both.
That type of information is worth millions, and there are many investment firms offering very lucrative positions to those that can identify a pattern that generates superior risk-adjusted returns.
Outside of very rare outliers, it doesn’t seem reasonable to assume that information that will generate outsized returns will be publicly available.