Proposal 9-77 in the '92 TCR and the associated comments in the '92 TCD resulted in the first rules in the NEC to prohibit the installation of switches in the shower or tub enclosure. Up until that time the code permitted weatherproof switches in that location. The proposals and comments requested that the switches within 5' have GFCI protection. The CMP only accepted in principle, and the rule in 380-4 for the '93 code only said; "Switches shall not be installed within wet locations in tub or shower spaces unless installed as a part of a listed assembly". In the '96 code this was modified to say that any switches in these areas must be a part of a listed tub or shower assembly. Proposal 9-86 in the '98 ROP would have required that switches and receptacles not be located within 36" horizontally of a bathtub or shower enclosure. This was rejected by the CMP with the comment that the existing wording in 380-4 for switches is adequate and that the location of receptacles is not within the scope of Article 380. In the '01 ROP another proposal, 9-74, was made to require switches be outside of the "bathtub and shower zone". This proposal was also rejected.
In the '96 code, 410-57(c) first appeared prohibiting the installation of receptacles in bathtub and shower areas. A proposal, 18-70, was made for the '99 code that would have placed a 3' limit from the bathtub or shower enclosure for receptacle placement. This too was rejected by the CMP. Another proposal, 18-46, was made in the '01 ROP to have a 5' limit for the receptacle location. Again rejected by the code making panel.
It appears very clear to me that both CMP 9 for switches and CMP 18 for receptacles are only intending that the switches and receptacles be outside of the bathtub and shower areas, but that there items are permitted to be installed immediately adjacent thereto.