Will there be a Drupal 6 version?
Considering the improvement in the Drupal.org captcha in the last three years, the effort spend to update MyCaptcha to Drupal 6.x is not proportional to the benefits it has. So, I'm sorry, but there will not be a Drupal 6.x version of MyCaptcha.
Why is this module not on Drupal.org?
There's already a CAPTCHA module on Drupal.org. Functionality should not be duplicated in the Drupal.org repository.
OMG! The image is unreadable!!!!
Visit the settings page on Administer » Site configuration » Captcha (admin/settings/mycaptcha/image) and disable some of the noise options (Double vision, Dots, Lines). See the page Image captcha settings for more information.