I suspect many lights with a medium to high lumen output (say, approx 600 to 3,000 lumens) are mainly used for searchlight-type of purposes, so I would imagine that lights in the brighter ranges would primarily be "throwers" with little "spill".
I'm thinking, though, that it could be useful to have bright lights with plenty of spill, to see what's going on off to your left and right (and above you), as well as a diffused hotspot.
Are such floody medium and high-brightness lights that sacrifice a lot of throw distance to provide good spill difficult to find?
They're not hard to find, just a bit pricey, sometimes. The term you are looking for is, "mule," and you can usually find some good drop-ins for sale on customs or CPFMP, or have one of the drop-in makers whip one up (Vinhnguyen is offering to make them, FI, and you get to choose the emitter and current). Overready also makes custom Peaks with mule heads. These areheads that put the LED close to the lens, with no reflector, for a pure floodlight.
For lower brightness, you can add a diffuser, either as a wand (think translucent traffic cone), material under the lens, scotch tape over the outside, etc.., or get one of many Zebralights with no reflector.
Depending on what you use it for, spill may be useful even with throw. For example, the classic focused Maglite beam has a very wide, even spill. While very dim, it gives you nearly 180 degrees of light, enough to illuminate the ground ahead of you, while pointing the spot into the distance. Much of this light comes from the shiny bezel ring, rather than the reflector. Many torches with polished aluminum (bare or silver ano) or steel bezel rings will do this.
Now, overall, there's not too much use for nearby illumination that is super bright, without a wall to plug into AC. As good as LEDs are, you sacrifice battery life quite a bit, but get little in return. It's not coincidence that so many torches have their high mode normalized to about what they can get for 1-2 hours, rather than the thermal limits of the LED and/or body..