Having flown with flares I can say I would rather have them than a landing light. You have more choice as to type of EOL at the bottom not being confined to a constant attitude landing. (if you flare with a light it tends to point up and you cant see the ground to level). You also if above 1000ft get more choice of landing site due to the improved lighting.
As to not using them due to the risk of a fire on the ground....I would rather be alive to watch the fire crew putting out a good blaze than sat inside the blazing remains of my crashed cab.