over the years I've seen various chord-style keyboard schemes. I've wondered why none have caught on - seems more logical than hitting individual keys.
Think about all the people you know that still have to look at the keyboard to type, that type just using one finger and one hand at a time, that still hunt for common symbols. None of this would work with a chording keyboard.
Unless you're transcribing, typing is not usually a limiting factor. This is especially true for programmers. For example I'm using three different keyboard layouts due to the commonality of languages around here and as a result I keep doing typos due to switching. I never bothered on improving because it's simply not a limiting factor.
What's even more ironic to me, is that we would have much simpler improvements to keyboards to make RSI and typing more efficient with minimal impact (I'm thinking ortholinear layouts - not chording!), but nobody really seems to care.
The keys are arranged in an orthogonal grid, instead of each row being offset from the ones it's next to.
On a similar note I was talking to someone recently about touch screen phone keyboards, and how compressing a qwerty keyboard onto a (relative to the size of actual keyboards) tiny screen with very little haptic feedback seemed like an awful idea that was used early on because it was easy to understand and since then we've just kind of stuck with for no reason. The person I was talking to agreed, and we were thinking of ideas of how it could be improved. Later I was talking to a my two brothers about it, who are more a bit more normal, and neither of them thought it was worth the effort at all (and they're probably right), and thought it was pretty daft thing to care about.
Long story short, if it aint broke, don't fix it I suppose
Edit: rephrasing for clairity
At some point in the sliding scale it becomes worthwhile to care about and implement