Imagine you want to water your lawn, and you want to upgrade your water pressure so there's more water coming out. The water here is analogous to light output.
So you go and purchase a system that outputs more water - this is the HID kit.
Now, you're supposed to also buy a new hose that is meant to spray the larger volume of water in a nice, defined spray - this is the projectors.
...but you don't. Because the hose (projectors) are expensive, hard to install, and you think to yourself fuckit.
So instead of using the proper hose, you get a garbage bin and just spray the shit out of everything. You're soaking your neighbour's lawn, their pets and children, and everyone around you, and ironically, the water that was meant to water your lawn is ending up everywhere else.
Projectors align the brighter light into useable light in front of you. Reflectors just scatter the light everywhere, you blind everyone in front of you, and you're actually getting less usable light.
Edit: Added picture - Reflectors on left, projectors on right.
