For today's installment of What's Wrong With Karate, let's evaluate stances.
These are the most common, though many other stances exist. The problem with all of these is that they are not entirely practical. Of the ones listed, all but nekoashidachi are too long and wide to be mobile. Nekoashidachi is too upright and leans too much on a single foot. Almost no karate stances have a balance of weight evenly between the feet, while simultaneously offering good mobility and lending the practitioner enough power.
The big problem is, these stances were never designed for combat. They were designed for doing drills, including kata, which are specifically to help strengthen the legs.
But karate teachers don't often teach it that way any more. You will see "self defense" routines laced with these stances, even in schools where the instructors acknowledge their uselessness in actual sparring or combat. You might even see students getting into these stances to practice with / against other martial arts training.
So, stick to these stances for conditioning and drills. But use real fighting positions when fighting.