If you agree that psychology isn't completely random and/or agree that self-fulfilling prophecy, by way of a sufficient volume of people basing their investment decisions on a similar belief (in this case: price pattern or "signal"), is something that can, and sometimes does happen, then you can't completely reject the claim that there is real value in analyzing chart patterns.

Hardly anything in this world is black or white, as much as the purely rational minded would prefer it not to be so. Regarding empirical based knowledge, at best, we can rate things (hypothesis or what-have-you) along a "spectrum of proof" and nothing has ever, or will ever, hit either extreme (if only because we can't prove that we even exist in the first place).

You're painting technical analysis (TA) as if it's pure black (provably bogus), but, statistically speaking, there ARE relatively strong correlations within the practice of TA that demonstrate statistical significance in predicting future price performance (compared to randomly assigning a guess as to whether price will move up or down), so, if anything, it's more on the white side of the spectrum, if not high up that spectrum.