Over the years, jazz made a conscious effort to liberate itself from the strictures of classic melody, harmony, and song structure. That's not wrong, but it requires concentration to enjoy, and in any event is only enjoyable in moderate doses. Swinging the pendulum the complete other way, jazz has always been conscious of melody, but melody in the absence of trajectory and a sense of movement and dynamics, can get boring pretty quick too.
Creed Taylor's CTI label always cornered the market on melodic-but-interesting jazz., while Manfred Eicher's ECM label took the other corner of melodic-but-exploratory jazz, and content that covered the overlap between jazz and "new music". Both labels released plenty of music that could be enjoyed without having to pay close attention, which sort of makes them contenders for "smooth jazz".
My sense is that any general antipathy towards smooth jazz is really antipathy towards Kenny G. Is Pat Metheny or Bill Frisell "smooth jazz"? If they are thinking about melodic structure, and not simply going through the moves, then I would say no.
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