Beyer's books sell because she is incredibly talented and writes Voyager better than the television writers ever did. The lack of Janeway simply shows all the more how good she is. Had Janeway not been axed, her books may sell even better even if Janeway was riding a desk at Command. As it is, we probably wouldn't have gotten Eden if Janeway were around;though Eden is far more interesting, she isn't the commander Voyager fanatics came to love. Were they reading before Before Dishonor, maybe not but they sure don't want to read now. I think they are being silly and fickle, but the franchise should have known that and not made the bonehead decisions they did in killing characters in Generations, TATV, and Before Dishonor.
Spock's death was done so much better than any other character. Plus at the time, fans probably weren't expecting any more trek anyways.