There's no reason to apologize of somehow feel guilty for quitting on bike commuting. It's one of those personal decisions that we all make, and we shouldn't feel obligated. If bike commuting makes sense for you, for whatever reason, do it, if not don't.

Also we don't have to consider commuting as an all or nothing deal. I bike commute most of the time, and use mass transit (the bus is convenient) other times. I have friends who commute only when the weather is good, or a few times a week.

One creative friend with an almost 20 mile commute worked out an ingenious solution that fits his needs perfectly. He bike commutes one way only. He bought a bike rack, and gave it to the driver of a car pool he joined. He car pools to work with the bike in back, getting there clean, dry and on time. Then unrestricted by a car pool, he can leave early or stay late, and enjoy his 20 ride home extending it if he wishes. If the weather turns sour, he still has the car pool option for the trip home.

In many cities, one way bike commuting is possible using mass transit, so for many this can be a good option.