I mean I use ctrl-w all the time in vim (delete word back while in insert or moving panes. Basically I'm hitting ctrl ALL the time). I also frequently hit it when I'm writing a HN comment or something. Though this actually isn't a problem because sometimes I just shouldn't be replying.

Edit: I do notice that pretty much everyone that does the caps remap is using OSX. Is this because most people are using macs or just because macs have different behavior? Either way, I'd rather use a vanilla command than a remap if efforts are basically the same (my pinky rests on shift anyways and it is easy to contract my finger. I also use ctrl-backspace when typing in HN and other forms).