What's with the sudden weather-sealing craze ?

I think we agree on the point that ideally, we want to have both lenses with weather-sealing and lenses with out on the market. That said, I don't think it's crazy to want lenses with weather-sealing. It all depends on how you use your camera and the climate you're living in.

I almost always pack the 12-50 with me and the main reason for that is its weather-sealing. Because of it, I can carry my camera on my sling even when it rains, and thus it's handy when an opportunity appears.