See, I entirely disagree with you there. Any 18650-powered Cree LED torch capable of producing upwards of 800 lumens can make a decent cycling light, with the biggest caveat being how focused the light is (obviously you want a fair spread of light, while retaining a forward beam) . I have a habit of going out after 10 p.m., almost regardless of weather and time of year. My usual route follows the UK's NCN 27 route, which is entirely unlit as it heads out from my hometown of Plymouth. My previous light was a 50w halogen powered by a 4400 mAh Li-ion battery, and while it was OK for night cycling, I found it didn't output anywhere near enough light for me to exceed around 20 mph. I have no idea what the lumens output of the halogen light was, but I cannot imagine it to be more than 500 lumen, and probably well below that.

With the Cree torch at that speed I am still able to clearly see the road ahead. As I mentioned above, in areas with street lighting, I switch it to strobe mode, which is exceptionally visible.

When you compare the lumen output of so many dedicated bike lights, you may be surprised to discover that some of the "good" ones only output around 600-800 lumen, while costing MANY times more than the Cree torch I use.

At the price of a Cree XM-L T6 torch you may as well try it and see how it works out for you.