Given that bare rooted ones have simply had whatever soil they were in removed prior to despatch, strikes me that I ought to be able to do the same with those that arrive in pots.
If the potted ones you buy have been lifted from open ground, plonked in a pot, and then soil/compost chucked around the roots then I agree - removing the soil makes no difference - in fact it will probably all fall off anyway, once you tip it out of the pot
If the plant has been raised, and grown on, as "pot-grown" then you are comparing apples-and-oranges:
A plant raised commercially and sold as pot-grown has been specifically reared to be planted out without root disturbance. You can plant at any time of the year, and the plants will grow away without check. However, plants that have become root bound in the pots may not grow on well, and it doesn't suit certain types of plants (for example Eucalyptus are very prone to never become stable in the soil if they have been pot grown to any significant size)
Bare-root plants have been grown specifically to be transplanted. For example, in the case of trees, they are often dug up and replanted several times before sale, or have their roots under-cut to force them to root shallow such that transplanting them will be successful.
Thus if you buy a pot-grown pot I would recommend that you plant it as such, and not disturb the roots. If the plant's roots are just surrounded by compost, and the roots don't fill the pot, then it is in effect a bare root plant with soil around its roots for transport and/or to increase its shelf life whilst it sits around in a garden centre - personally I would avoid those as no telling how long they have been hanging around, and I would buy freshly lifted bare-root plants instead