I think the third one is correct in that we should be tired of all this:
Am I the only person on this planet who is tired of those abstract fancy theory?
Aren't these statements just very reductionist?
Someone could say that Boxing is just 4 punches: jab, cross, hook, and uppercut.
Is that what Boxing is? What about footwork, head movement, guarding, clinching, and the rules they oblige by and the nuances?
If Taijiquan is just 6 harmonies, 8 gates, 5 steps, then where do leg sweeps fit in? Where does Qinna fit in? If you pierce someone's throat with your fingertips, which of the 8 Jin does that fall under? If you stomp the side of someone's knee while throwing them, where does that fall under?
I can endlessly create a list of stuff found in someone's Taijiquan that doesn't neatly belong to those things. And if someone does argue that it belongs in one of those things, I highly doubt they get mentioned in writing such as the "classics".
I suppose one could argue that everything that doesn't neatly belong in those terms is simply not important, but I think that's code for "we don't have that stuff because we lost it all."
When people say Taijiquan is [insert blank] and is only that set of things, my reaction is just: "That's it? That's all you have?"