The world of money and business is aimed at gaining more material satisfaction and power.
When you work, you use your conquering power to grow materially and gain more wealth.
The primary goal for working is to make money.
If you take this motivation away in the world, who would still work long hours in businesses and organization?
You would shift your activity to a more creative field if you can or simply relax in what you do and still do it. That's possible.
When you practice yoga, your targets are totally different.
Sure you can focus on the long term vision of having your own yoga studio but the primary goal of yoga and any form of spiritual discipline is not material wealth; it is self realization, inner growth, health, vitality, awareness, love, joy, spiritual power, etc.
These are your targets.
The moment you focus on yoga, you naturally transfer part of your energy and ambition to non material goals. This is why your level of material ambition can drop.
Another element has to do with the fact that yoga is a "soft" approach.
The primary goal is to develop a higher sense of clarity and inner harmony.
This goal is synonymous with spiritual development.
This was and still is the original purpose of yoga.
With this "soft" connotation behind yoga, you tend as well to drop your level of conquering power and ambition.
This is why the "power yoga" stream was born.
It is aimed at "compensating" this softness and give yoga a new "power" connotation.
This connotation seems to fit better with the needs of modern life, driven by ambition, business or career goals.
When you start practicing yoga, you literally tend to shift your life's main targets and focus to developing inner values and skills rather than material wealth.
Now, this is the traditional story behind yoga.
The way you can practice it in the west and in modern times is by unifying all streams.
You can have it all, simply in a different balance.
Every aspect of your being needs to be fed and if you notice a gap somewhere (for instance an ambition gap) and you have the need to fill that gap, then give extra attention to your career or more material goals.
All aspects of your life can be nurtured.
If you feel a gap somewhere, simply focus on actions and activities which do give you what is missing.