I would guess cheapness.why would you even be looking at a light like that???
I used to use nothing but cfl's and the good ones at that. 105W 6900 lumens at 6500K, till i bought a 150w hps econolight. i've gotten much better results with the 150w even for the veg period. the bottom line plants eat light its their food, and just like all other living things the more u eat the bigger u get. You can put all the cfl's you want around a plant and still not get the kinda lumens u can get from this 150w hps. Adding more cfl's doesnt increase your lumens, you can have 50 cfl's but you only get whatever the highest lumen output bulb u have in short 1ea. 105w cfl puts out 6900lumens and 5ea 105w cfl's still only put out 6900lumens adding more bulbs just spreads out the light it doesnt increase lumens.