No, actually, it's called
loss aversion. People tend to strongly prefer avoiding losses relative to acquiring gains, even if both forces are "strong". This has generally been understood as the source of violent declines (as well as rises) that are more frequent in bear markets, for a few centuries of history. (Interestingly, newer studies discount the phenomenon of loss aversion to instead prefer a competition-oriented model - behavioral finance is still an evolving field).
And also no, sharing "investing strategies" does not make them any less valid; on the contrary, technical analysis "works" because people know about it (i.e. self-fulfilling prophecy) -- it's the exceptions that get you. People have been screaming about
PE10 for the last couple of decades -- look how well that worked during the internet bubble and financial bubble. Now if someone wants to sell you a "proprietary investment strategy" or "wants you to invest in his strategy that he can't disclose because ... well, it's secret", those people you run away from, 10-foot pole or no.
"This time it's different". No, it never is.