Neither do I. But if I was in charge, and an idea for a next generation space ship was brought to me, and I was told, "By the way, we can't launch in the rain.", I'd have laughed them right out the door!
The first really bad-weather launch was the Apollo-Saturn used on Apollo 12. That one gave me the willies when it got hit by lightning on launch. You just don't light those candles in a thunderstorm.
This isn't atmospheric flight (although there are certainly weather restrictions there as well). The rules are different. The environment is a lot less forgiving. I'm not sure an all-weather launch vehicle with 100% guaranteed safety is in the cards, for NASA or private industry.