That seems odd to me. Historically, Ducatis are set up for just about that weight of rider. That's what I weigh, and one of the reasons I bought and have been so happy with my Monster is that it fit me perfectly right out of the box.
Maybe newer ones are set up differently; I don't know. But I'd get a second opinion before having any work done to "fix" it.
1993 Ducati M900 Monster "Patina" (265,000 miles, killed by minivan 30Oct17) -- 1995 Ducati M900 (wife's bike) -- 1979 Vespa P200 (daughter's scoot) -- 1964 Vespa GS160 (160cc 2-stroke) -- 1962 Maicoletta scooter (275cc 2-stroke) -- 1960 Heinkel Tourist 103A1 scooter "Elroy" (175cc 4-stroke)