what that tells us is that this tree was kept in a pot that was too small for too long, which caused the roots to start to circle around. When it was moved up into a larger pot, it was either too late to straiten the roots out, or whoever did it did not take the time to do so.
I don't think there is anyway of making this look like the typical radial roots that are prized, short of layering above that mess.
Alternatively, if you like how it looks, you can make it a focal point and expose them even more. But most bonsai people would not find it very appealing, I think.
- bob