This isn't quite true and you've pretty much identified the reason why. Academics are not investors and their objective isn't to profit but to publish their research.

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