I'm not quite sure what "Someone" was trying to say? So I'll just blather on semi-randomly.
There are so many different brands, types, formulations, applications and variations in automotive finishes that it isn't realistic to make any sweeping generalizations.
While it may be true that the resin base for SS coatings is generally clear before pigments are added that is not the same as saying SS and CC are the same paint. They will be similar, at least within a given product family, but have different functions and are generally formulated differently.
Some coatings can be used as either a SS finish or a base for a BC/CC finish. Some can't. It depends on the particular manufacturer/product line/formulation.
Some CC finishes can only be used over a specific BC.
Some colors and effects are only available in BC/CC systems.
Whether or not you chose to CC over a base paint that can be either SS or BC depends on the look you wish to achieve and how you want the finish to perform.
Many people feel that certain cars and colors, especially very traditional classics, look better with an SS finish.
The amount of texture that accompanies single stage paint jobs is dependent on the paint formulation, application conditions, reducers, additives, the gun, the shooter, etc. It is also very common to wet-sand between coats when doing a high-end custom finish.
Hope this makes some semblance of sense.
PC.