IF the 'correct' meaning (i.e. 'dictionary definition') of the word "lamp" 200 years ago referred only to the 'function' (i.e. 'something which produced light', or somesuch) then I would agree with you.I think that is unfair, and similar to Winston's use of 'transformer' to only mean what was available at the time and not to later items with the same function. ... If lamp means 'that which shines' then surely its use for the 'bulb' is correct and not the whole assembly.
However, I strongly suspect that the definition 200 years ago would have specifically related to oil lamps, rather than just to the 'function'. If that were the case, then to use the word to refer to any other source of light would have been 'incorrect' use of the word at the time - an 'evolution' which I personally would find totally reasonable/acceptable, but which you would presumably oppose?
Similarly, IF, 70 years ago, a "transformer" had been defined as a "voltage converting device" (rather than with reference to a wirewound component that worked by induction), then it would have been appropriate to continue using that word for SMPSUs etc. - but, of course, that wasn't the case
Kind Regards, John