When most people think of bare carbon they actually mean having the laminate visible with a clear coat layer.
The clear coat is there to protect the carbon laminate, real bare carbon is not recommended. The resin will get degraded by UV and moisture and significantly reduce the life of the frame.
Also most frames use fillers at the joins, which are often painted to be less obvious, these areas can look quite ordinary when the fillers and paint are removed.
It is also difficult to remove the original paint without damage to the laminate, unidirectional plies can be down to 0.05mm thick. Paint strippers and blasters can damage the laminate so it is usually done by hand sanding. This makes the process very labour intensive and thus expensive.