Sure it can suck to ride your bike on a cold wet day like we get in Seattle, but the right gear can help a lot... and I'm not sure anyone is saying, "If you buy a bike you MUST sell your car and do everything on the bike". I'm taking the bike as a challenge to myself, trying to do all I can on it. But if one day I'm just not up for it or it's just pouring, or the load is to big or too far. That's what car share is for. If everyone did similar we'd have a lot more pleasant cities.
Good gloves for ski or bike are inexpensive. You just need to think to buy them.
If it's really cold when you commute, just a pair of jeans and any sweater or jacket is ok, as you're cycling anyway.
But when it's raining or wet, you would rather just stay at home, get your car, or wear shorts if you're already outside.
And when it's hot, still shorts , but get a bottle of water. The biking will make a light breeze to cool you down.
But it's still up to you to find what you like.
For example, some persons do need beanies too, while others will be on beach outfit all year long.