But isn’t 10,000 daily steps a better goal?

I always see or hear it referenced, so why doesn't Paceline use it?

As surprising as this may be, this value of 10,000 steps per day was coined to help sell pedometers (check it out here). In fact, recent publications from notable institutions, such as this one from the Journal of the American Medical Association (JAMA), have called into question whether the 10,000 step goal reflects an accurate measure of physical activity. As a result, and by recommendation of the American Heart Association and World Health Organization, we've set the desired goal to at least 150 minutes of elevated heart rate activity spread throughout the week.