reCAPTCHA has become increasingly less user friendly over time, back when it was first released it was very usable but sadly it appears as though in their attempts to slow down the bots they've sadly had to make it as bad as what it replaced.
Edit: And perhaps I rather missed the main point. As said by others, reCAPTCHA is broken and from what I remember reading it has been for a while now so unless they take a dramatic change in approach I'm not sure how they'll improve it without being reduced to making the text so unreadable that you'll have to spend ten minutes examining the reCAPTCHA pixel by pixel.