Again, I ask: have you read the Tau Manifesto? If not, I suggest you do that, as it makes the case there much more clearly than I could here.
The point being: for children learning the basics, the odd 2 or 1/2 here and there masks the underlying relationships. But don't take my word for it-- read the manifesto.
I read it a few years ago. I disagree. It's like saying removing a seldom used letter from the alphabet would mean kids learn to spell better.
The whole point of learning is to learn to read things and understand them. That means looking behind 'fluff' like 2, or 1/2, and understanding the concepts.
The right sentiment, but I don't fully agree with this.
There are a lot of people who aren't kids, aren't mathematicians, but have to deal with maths all the time. In fact, our own field of Computer Science has a lot of math.
Now, I can't speak as a real mathematician (though I know more maths than most people), but I can definitely speak as a CS major - learning to use radians was never natural for me, and it is the basis of most of calculus. Had I learned it using Tau, I'm guessing it wouldn't have even been an issue. It wouldn't even be something I have to "learn". It just makes sense - one half of a circle is one half Tau.
Far more important step for mathematicians would be to switch from base 10 to something more useful like base 8.