Gotcha. And btw, in re-reading my post, I realize that my tone was unintentionally poor -- it definitely wasn't meant that way. My apologies!
I've actually heard a number of traders suggest something along the lines of "trends tend to persist," or "once something's in a trend, you should assume the trend will continue until proven otherwise." Maybe that's not really meant as a statistical fact... but rather a practical assumption and useful guideline when trading -- i.e., "you're better off not considering going countertrend unless and until the prevailing trend has clearly been broken... as evidenced by a failure to establish HHs/HLs (for an uptrend)."
Just as I continue to suspect that a lot of the debates here in ET stem from semantics... I also feel that another source of contention arises between more "discretionary" traders vs. more "algorithmic" traders. The majority of discretionary approaches, tools, patterns, indicators, etc. -- even TA itself -- cannot be "proven" to work from a rigorous, statistical standpoint, imo. Most that I'm aware of cannot be applied successfully in a vacuum... and so there's simply too many other variables and too much underlying context to perform that type of proof.
I'm not even sure that a simple, widely used concept like "support & resistance" can be properly modeled -- much less, "strong" or "weak" S/R. Sure, you can use something like pivots, find various ways to approximate S/R, define certain cases mathematically, etc. -- but any resultant code would likely be very constrained and inflexible vs. what our eyes can see. Probably can't be "proven" to "work" -- but a lot of traders seem to find value in using it as one "tool" of many.