During Frieza Saga in Dragon Ball Z, when they wished for everyone killed by Frieza and his men to be revived, why weren't the other Saiyans, like Goku's father and mother, be revived from the dead?
Because the wish was for Namek only.
During the final battle of Gokū and Freeza on Namek, Mr. Popo used the Dragon Balls and wished for the revival of all the people on Namek who were killed by Freeza and his men. (Granted)
This means of course anyone who was killed, either directly or indirectly by Frieza and his army and were not on Namek was not revived.
Should also note that Shenron's power can't surpass his creator and reviving all of those who have been killed by Frieza universe-wide would no doubt be beyond Kami's (and later Dende's) power since there are probably untold millions killed just from being on a planet Frieza blew up.
Super Shenron on the other hand can grant a wish without limitation, so would be the better choice for such a wish (Beerus has claimed Super Shenron could destroy an entire universe if wished to, quite sure reviving a whole bunch of people like that is dwarfed to the opposite of destroying a universe)