One can regard an event as being on-the-whole good without having a positive emotional reaction to it. Similarly, one can take enjoyment or satisfaction from something while acknowledging that it was on-the-whole bad. For example, some tribulations might be unpleasant but cause the sufferer to come out at the other end a better person; they might then have a negative emotional reaction to their pains while upon reflection endorsing the suffering.
It seems to me that this kind of distinction is what would be needed to defend the taboo against speaking ill of the recently deceased as anything more than an arbitrary social convention. We would say that while one might think that the death of Margaret Thatcher, or Hugo Chavez, or some such person was all-things-considered good (an argument which seems far easier to make about Chavez, given that at the time of Thatcher's death she had been out of power for almost 25 years), there is something wrong with having the emotional reaction of pleasure to the death of a fellow human being.