I commute to work on bike every day, but I still am a happy member of my city's bike share program. Even though I have a bike locked in the garage under the building, I use bikeshare to go to meetings at other buildings in the city during the day. I would rather that my personal bike remain safe in my office building's guarded garage, rather than parked on the street. Also, heading into a meeting, it takes me 3 seconds to park a bikeshare bike at the station, as opposed to several minutes locking up my personal bike using a U-lock and cable. I know of other regular commuters who switched to using bikeshare for their commutes--the bikes may be slower, but you don't have to worry about maintenance or theft.

Essentially, I pay my membership fee so that someone else bears the risk of owning a bike in a city filled with vandals and thieves. It's a good deal.