In case you were wondering: In 1997, the World Health Organization ranked Hungary 66th out of 190 countries in overall health care system performance, behind Austria, Slovenia, and Croatia, but ahead of Ukraine and Romania. (Also ahead of FR Yugoslavia, which still existed back then. As far as I can tell, they haven't done a new ranking since.)
Because one of the adjectives is attributive (it stands before the noun) and one is predicative (it says something about the subject, the Y in an "X is Y" template).
Attributive adjectives do not get number or case endings (unless they stand alone, without a noun, as in magasok "tall ones"), while predicative ones do.
(Oddly enough, German adjectives work exactly the opposite way.)
"Medic" is not exactly the word you are looking for here, as it is a general term referring to various people, with varying degrees of training, involved in the medical professionals. "Physician" is the precise word for this sentence.
Are Hungarian physicians "not good'? In fact they are amongst the finest in the world.