If LEDs are all bad, I doubt that the manufacturers would put them in their new vehicles.
No one is saying all LEDs are bad. Like nelstrom said, OEMs are using purpose built housings, not LED bulbs stuffed into the same housings as they use for halogens. The light emissions from a LED bulb itself is completely different than a halogen or HID (and HID is different than halogen too).
To put it in very simple terms, LED light is very directional, whereas halogen light is omnidirectional. All the flutes in a halogen reflector and lens is designed to collect and focus that light into a specific beam pattern.
Putting LEDs into that same housing results in lots of light scatter, and a poorly defined beam, even though it may appear brighter.
Far too many people have a misguided notion that brighter is always better, and it's simply not true. Brighter also means increased glare and reflections, along with increased blinding of oncoming drivers. This all is greatly increased when coupled with a poor beam pattern, and all results in decreased useful light and less visibility for you.
Many people also don't realize that bulbs degrade over time, and reduced output compared to new. A lot of people complaining of crappy stock lights would see huge gains just by using new clean housings and a new set of basic halogen bulbs fed with proper voltage. Usually with a relay kit, as the 30 year old wiring in your truck has also degraded over time, no longer supplying the full 14 volts to the headlights.