I think GRRM very carefully made by both the positive and negative parts key to the framing of Qyburn; he's quite clearly both a brilliant scientist who rebelled against obsolete and conventional ideas which did not work, and, a monster who is utterly indifferent (or so nearly so as makes no difference in practice) to the suffering inflicted on the pursuit of his research, either directly or in his efforts to maintain the support he needs to continue his work.

GRRM tends not to make unidimensionally good or evil characters in ASOIAF (there's a few that seem that way on the evil side, but they are mostly also ones we don't know as much about.)