infantry powerless against starfighters and tanks

Ever notice how in this game, weapons designed for use against vehicles seem to hardly put a scratch in anything? You shoot at a tank or fighter with a missile launcher or concussion grenade, but little or no damage is done. Its especially bad with the missile launcher, because it is able to track a starfighter but when it impacts it does nothing. same as when you use one of those round gun turrets on a star fighter, it does nothing! yet the ship weapons are incredibly powerful. star fighter cannons can kill in one hit-even with blast damage! anyone else want to vent on this?