One reason why raw data manual flying might be frowned upon by the higher levels is precisely if people cannot decide when it is appropriate and when it isn't. RNAV procedure? ILS with a low cloud base and/or poor visibility? Independent parallel approaches? Use the appropriate level of automation - and that is the highest one, just as it was originally intended. Raw data VOR/DME procedure? ILS in reasonable weather? Visual approach or visual departure? It's your party, disconnect whatever you want and fly the plane. Performing an RNAV GNSS approach with no FDs or in TRACK-FPA is just as wrong as performing a visual approach in NAV. The FCTM is very explicit on the correct techniques for every type of approach, with some further useful comments provided as explanations to the steps listed in the FCOM Normal Procedures - Approach guidance management chapter. Plus any company requirements in the OM-B (for example, there's a certain major European carrier which permits flying a raw data approach or an approach with manual thrust, but not both at the same time).