I would say tech probably has worse median outcomes but better right tail outcomes than finance.
It's basically just a textual explanation of Markowitz optimization, known since the 50s.
To me it's as interesting as a trader telling you his secret is "to buy low and sell high".
The book is highly recommended even if you don't implement half of what he's suggesting as it's based on hard-won experience. His Principles tweets are largely expounding on what's in the Principles book if you don't want to buy it, with some regurgitation which I felt was kind of marketing driven to promote book sales. Definitely worth the read.
From mid 2017:
https://www.bloomberg.com/news/features/2017-08-10/bridgewat...
> Since the beginning of 2012, Bridgewater’s Pure Alpha II has posted an annualized return of 2.5 percent, according to a document reviewed by Bloomberg Markets, a far cry from its historic average of 12 percent. It’s down 2.8 percent this year through July. (A smaller Bridgewater hedge fund, Pure Alpha Major Markets, has fared better, as has the company’s long-only product.)
That said, Bridgewater hasn't done that great for awhile.
Why?
I tend to find it okay to compare Sharpes so long that the returns exhibit a somewhat close distribution.
I would expect both the S&P and an equity market neutral L/S to have normally distributed returns.