When I lived in Seattle I bike commuted and also did the Seattle to Portland ride for about 15 years.
I’m a cyclist, but disagree with the “cycling community” on almost everything. The STP clogged a large portion of the state. Many in those areas showed their appreciation by scattering tacks along the sides of the roads. It’s why I avoided being one of the early starters. :-)
And communting, you are correct. I would drive in if it was raining in the morning, I didn’t mind coming home wet, but I didn’t want to arrive at work wet.
Cycling is a great way to stay in shape and not destroy your knees. It is also a great way to commute. But it needs to be seen as what it is - people using the roads for free.
The great majority of bicycle commutes are short, under five miles and frequently much shorter than that. Over the years, I have had two jobs to which I commuted by bike. Both rides were under two miles. Over that range, biking was often faster than driving, as I sailed along while cars sat in traffic. Which brings me to the overarching point that I now make when the subject comes up....
The key is building liveable, walkable, bikeable neighborhoods in mixed use areas or close-in suburbs. Bicycle commuting is not primarily about getting spandexed bike warriors 20 miles from suburban cul de sacs to downtown. It is, or at least should be, about building cities that are not predicated on everybody moving by car. Many people will still choose to drive, or have to drive. But if we plan well, many of us can have better options. Older, more dense cities with traditional downtowns have an advantage here.
Did I bike to work when the weather was bad? No, of course not. I grabbed a bus or metrorail. I live in a close-in neighborhood where this is practical. Here in DC, over 12 percent walk to work, and another three percent bike to work. Even higher percentages take metrorail or busses, and over a third of residents don't own cars. But that's citywide. In a neighborhood like Capitol Hill, the numbers are much higher.
The suburban automobile supremacists tend to assess the practicality and importance of alternative transportation from the vantage point of their own cul de sacs. That leads to a misperception. The importance of alternative transportation to them is all the potential vehicular traffic that is diverted in closer-in neighborhoods, due to people with much shorter commutes walking, biking, or taking public transit.
Perhaps the bike lobby has gotten its PR backwards. Instead of "ride a bike to school/work day," let's have "everybody take a car day" and let the folks coming down I-270, 395, or 66 sit in a jam for an extra hour or two.