Interesting how people equate "I don't like x" with "x is wrong"... If that's the definition of "wrong" that people use in discussions, I see why science has such a hard time getting through to the public.
1) The author here is being lighthearted; your comment implies instead that he's being a demagogue.
2) This sort of pattern is far more common in "public" discussions such as public policy than in science, so I think you are directing your ire incorrectly.
The claim that pi is wrong is a claim about pi's inconsistency and inefficiency as a matter of mathematical language design. These guys aren't dumb enough to confuse this as a claim about formal correctness. Instead, they're playfully co-opting the rhetoric of formal correctness.
I can reformulate all of physics to accept the Earth as a constant reference frame. It will be isomorphic to current physics based on being set in inertial reference frames, and therefore every bit as "correct" as conventional physics. There will be no place where conventional and Earth-centric physics will disagree about the result of an experiment. However, Earth-centric physics is wrong. It produces terrifically complicated equations for even simplified versions of predicting the orbit of a planet around a distant star. The speed of light is anisotropic. If you really get down to specifying things precisely it has to include rather a lot of kludgy compensations for variations in the Earth's rotation that are nevertheless perfectly definable. It isn't a useful way to approach physics. It is "wrong".
The previous paragraph isn't metaphorical. I am not saying "it is theoretically possible to reformulate all of physics to be Earth centric". I'm saying that one can in fact mechanically translate all physics equations into such a framework, and similar transforms occur all the time (although with better cause). I'm not just being rhetorical, though of course I am, it is also literally true. There is a set of equations that corresponds to the reference frame I am describing.
We select our representations of equations for two major reasons that I can see: One, to minimize the number of symbols necessary to express the concept. "distance = velocity x time" encodes a number of assumptions into it to shorten it, including a wrong idea about reference frames, but we still teach it because it's simpler than the relativistic version (and a hell of a lot simpler than the Earth-centric version!). Second, to enhance the human understanding of the situation being represented by the equation. That's not entirely separate, obviously, but they're not quite the same.
And I would argue tau wins on both fronts, and I for one plan on adopting it in my code. It's better.
It's better.
See, you already agree with me. It's not "right", it may be "better" (though I question that fact, too.)
5. The fact or position of acting unjustly or indefensibly;
6. Not right or satisfactory in state or order; in unsatisfactory or bad condition; amiss.
7. a. Not adapted, according, or answering to intention, requirement, or purpose; not proper, fitting, or appropriate; unsuitable.
Any and all of which, but particularly #7, apply to the use of the term wrong in the tauday site.
Pi is [not adapted to purpose, not fitting].
See?
More to the point, in the online OED as I see it, definitions 1 and 2 deal with physical shape, 3 and 4 deal with moral character, and interestingly, my 5) differs from yours, being given as follows :
5. a. Not in conformity with some standard, rule, or principle; deviating from that which is correct or proper; contrary to, at variance with, what one approves or regards as right. b. Not in consonance with facts or truth; incorrect, false, mistaken. c. Of belief, etc.: Partaking of or based on error; erroneous. d. Of a painting: having an erroneous attribution.
Given that it's not until we get to 6 and 7 that we find definitions regarding quality of 'state or order' or 'appropriate' and 'suitable', I think readers are quite justified in finding the OP's use of "wrong" to be at least very freely used -- which was, of course, part of the whole point.