Yes. If you really want to make quantitative folks anxious, say things like:
Have no fear that you are on a fool's errand in subscribing to this process (or the concept of long/short in general); you can rest assured that you are in the company of the most successful quantitative traders and investors, large and small, in the history of this industry.
From the outside, it really seems like the finance industry is a mess as an intellectual enterprise. Take, for example, the recent subprime mortgage debacle, and global melt-down, freezing of credit markets, government bail-out, etc. And the 2007 quant-crisis, the dot-com bubble, LTCM, and the list goes on. My earliest memory is Black Monday, 1987. CalPERS moving away from hedge funds is another example that comes to mind. The assumption that doing what everyone else has done is not so clear to me, but then I don't work in the industry.
My training is in physics, and engineering (by trade). It is safest not to think you know what you are doing, unless you have data to support it, and there is a pretty high bar to actually "prove" something (e.g. the tremendous effort to show that gravitational waves, as predicted by Einstein, actually do exist). Even the term "first principles" has certain connotations. If I'm solving a problem in electricity & magnetism, for example, it might mean laying out certain assumptions to justify use of Maxwell's equations, and then applying them rigorously. In the field of finance, since I don't work in it, I don't know what "first principles" implies.
It is nothing personal, but it just doesn't matter who the authority is or what everyone else is doing. The Richard Feynman of finance could declare that multi-factor long-short equity strategies work, but until I see at least an existence proof that has traded real money for 5-10 years (or even a backtest on Quantopian), I'll be skeptical. I'm supposing that Jonathan has actually worked on these things, but by NDA, can't give a personal account, or even answer the question of whether he's seen one in action first-hand and what it looked like.
One problem here is that there may be a survivorship bias at work. The raw data on multi-factor long-short equity strategies over the last 30 years may be that typically they fail (or grossly under-perform relative to a benchmark). My hunch is that Quantopian is hoping that they can be one of the winners, and beat the statistics.