Great question, the simplest answer is: because more isn't always better. Comparing lights solely by lumens is kind of like comparing bikes solely by how much they weigh...sure, no one wants to pedal a boat around, but a 12-pound road bike isn't going to fare very well at the bike park.

Think of it this way: You can drive a car comfortably at 80mph with headlights putting out <2,500 lumens (legally limited by the DOT), you should be able to ride a bike at 30mph without 10,000+ lumens, the key is putting the light where you actually need it for the application.

Compare a ~2,000lm light like our Trail Evo to something with 8,000lm. That's 4x the light output, which means ~4x the power required to run it for the same period of time, which means you need ~4x the battery, which is the biggest contributor to weight so now it's a lot heavier, and a lot bigger, making it harder to mount the batteries somewhere, since it would then have to be an external battery. ~4x the power means ~4x the heat, which means you better be moving FAST or the light head won't stay cool enough and it'll almost immediately have to start pulling back power to keep the light cool enough to run, which means you're not getting all those lumens for very long. That "crazy bright" light is now not remotely optimized for bike use all to give you more light than you actually need. 

We're not trying to make the "the world's brightest bike light" because it's a meaningless title that doesn't produce the best product. We optimize our lights to produce exactly how much light you need so that we can balance all the design criteria around the specific application: twisty trail riding handlebar light, high-speed pavement, and everything in between.