Meaning you got lucky. Normal dice rolls make laser grenadiers (you will note I advocate no changes to the heavies) not worth the 21 points. Every other squad that has such a short range shoots more often (shotguns, or Sov assault rifles) and usually has grenades or some such to damage vehicles (and often nerf cover). My first Warfare battle I got lucky with the lasers, too, but I knew that it was luck, and they've rarely been worth the 21 points since. (Please note that my opponents aren't stupid enough to allow me to get Sustained Attacks with said unit, either - they know what happens if I do.)
The least FFG could do is knock the laser grenadiers' point value down to, say, 14.