

You get a slick sided forend that doesn't require being covered in plastic rail covers(although people still do it anyway). You can attach your currently owned accessories with pic rail sections that are compatible with any manufacturer's keymod forend. It's an open standard that doesn't cost manufacturers some goofy licensing fees to implement. The backlash(not sure if it's caused by ignorance, or just people "set in their ways" from a whole 5 years ago) over keymod is mindboggling. Unless you really want to go back to the days of needing a serial port for your mouse, AT connector for the keyboard, parallel port for a cable with a centronics plug on the other end for the printer, a gameport adapter for a joystick, and who knows what other random connection standard for any other devices you might have. Hell, it's the same reason USB became a standard for computers. Is that clear enough now? There's simply no reason for manufacturers to not switch to a standardized accessory attachment system that doesn't require 3-5 feet of pic rail that will go unused or needs to be covered up with even more crap(nevermind the actual bulk of the rails themselves) compared to a slick forend that doesn't require going back to the manufacturer a year later to figure out what thread pitch they use for their screws or rig some hokey nut to the underside of the rail and hope everything lines up with your rail section in the spot you want. Which are also likely not compatible with this:

The KEYMOD 13 though sells for well under UK200 and offers many of the benefits of more expensive gas models It makes use of the tried and tested Western Arms gas blowback system, ensuring reliable performance with a plethora of aftermarket parts and accessories (one of the team still has an original WA AR that’s been upgraded and still.Because rail sections and accessories for this:

Samson Manufacturing is the premier manufacturer of firearms parts and accessories, helping customers find solutions to their needs. Rail covers help, but the KeyMod system has truly revolutionized handguards. Specializing in the AR-15, HK, Kalashnikov and other MSR enhancements, Samson offers free-floating handguards, optic and magnifier mounts, fixed and folding rifle sights and more.

Put up some pictures of the bottom of the accessories. In essence, with a KeyMod handguard, you can hang an accessory using key-shaped cutouts in the position you desire without all that extra unused Picatinny rail. My bet is the nuts are reversed and you don't understand how KeyMod works. Stuff assembled and installed correctly doesn't fall off by itself. Even with the screws barely tightened they won't fall off. This leaves the rest of the handguard streamlined for less weight and bulk.
