You cannot travel at any desired speed! You can't travel a million miles an hour in a 5 knot wind because you desire it.

[. . .]

Tao simply does not say the things you people are trying to make him say. He is agreeing with me on every point I've discussed here.

You yourself quoted him as saying it. As you indicated, you can only make him agree with you by saying that he didn't "mean that literally".

At the end of the paragraph, he repeats it even more explicitly: "By alternately using the aerofoil and hydrofoil, one could in principle reach arbitrarily large speeds and directions, as illustrated by the following diagram:"

Are you saying that he didn't mean "arbitrarily large" literally?

ETA: In the next paragraph, he writes

It is reasonable (in light of results such as the Kutta-Joukowski theorem) to assume that the amount of lift provided by an aerofoil or hydrofoil is linearly proportional to the apparent wind speed or water speed. If so, then some basic trigonometry then reveals that (assuming negligible drag) one can use either of the above techniques to increase one’s speed at what is essentially a constant rate; in particular, one can reach speeds of n|v_0| for any n > 0 in time O(n).

Emphasis added. v_0 is the velocity of the wind. There's no room here for reading this as anything other than literal.