SAW was...
1. not accurate enough
2. location easily detected by the enemy
3. very high consumption of ammo
SAW was...
1. not accurate enough
(It was a belt fed light machine gun, not a sniper rifle. It is meant to control an area and to lay down a base of fire to support maneuver)
2. location easily detected by the enemy
(Ok, you have found a machine gun well emplaced and pouring fire on you...your move)
3. very high consumption of ammo
(That also means it sends a LOT of ammo in the right direction. That’s a feature and a blessing to a grunt needing fire support, not an problem. That same wasting ammo complaint saddled the 7th Cavalry with single shot Springfields when the Cheyenne and Sioux had Henry’s and Winchester 66’s)
Just for fun... an inaccurate M-249 at work against an RPG shooter. An oldie but a goodie.
https://www.liveleak.com/view?i=3ce_1374246544
Read a book called “No True Glory” about the battle in Fallujah, and a SAW gunner got killed in a house, and his gun disappeared and was in the hands of insurgents inside they building they had to take.
The Marines were pretty nervous about going up against a SAW taken by the enemy...they know what the thing can do even with those drawbacks.