A clickie is more complex, ergo, more expensive than a twistie, and the G2 is meant as an economy offering from SF. Also, a twistie is much more reliable than a clickie (again, because it's far less complex) and makes the G2 what it is: a reliable sturdy, economic light that you don't need to worry about. I guess they figure if you care about a clicky, you'll upgrade to a higher grade light like the E2e, or shell out for the clicky tailcap they offer. I'm sure the G2 will see periodic improvements. But I think it is pretty well evolved for what it is meant to be.