One of the more contentious elements of the Dragon Ball franchise is ironically its main hero, Goku. While he's considered one of the greatest warriors in the series' universe, his fighting skills far away his skills as a family man. This sees him many times turning to training instead of being a father and a husband. Worst of all, this sees him completely overlook another family member.
Goku's "grandfather" Gohan was the elderly man who adopted the Saiyan when he came to Earth. Despite raising Goku and inspiring the name of his firstborn son, Grandpa Gohan is largely forgotten about in the series' narrative. This is especially noticeable given that Goku never visits him in the afterlife. For as morbid as this sounds for such a close family member, there's actually an explanation beyond Goku's own negligence.
Goku's First True Family Member Has Been Forgotten About
Though Bardock may have been Goku's biological father (and subsequent retcons to the character arguably neutered him to be a more loving individual), he wasn't nearly as caring a guardian as the human Gohan would be. Though bewildered by the baby Goku's having a tail, the elderly Gohan took the alien child in nonetheless and raised him as his own. This would eventually result in tragedy, with Goku accidentally killing his "grandfather" one night when he inadvertently transformed into an Oozaru (the Great Ape form connected to a Saiyan's tail). He would come back at one point during the original Dragon Ball, however, as he was revived for one day to participate in bouts at the behest of Fortuneteller Baba. This led to a tender reunion between him and Goku, though it would sadly be one of the last.
Apart from that, Grandpa Gohan has little to do with the plot of the franchise. He's largely seen in flashbacks or addressed by Goku, with Goku realising that his own sense of morality stems from what his adoptive grandfather taught him. The naming of Goku's first son is the ultimate testament to Gohan's legacy, with the infant smiling anytime the deceased man was spoken. As a result, Goku decides to name the boy Gohan in his honour, despite the fact that he planned to go fishing. This lackadaisical attitude toward family responsibilities has had many of the series' fans mock Goku's paternal instincts, and that extends to Grandpa Gohan. Despite his having connections to do so, Goku never seems to visit his grandfather in Other World or have Fortuneteller Baba revive him for a single day from time to time to celebrate major events as a family. The same goes for using the Dragon Balls to wish the old man back to life, which Goku frequently does for people who are honestly mere sparring partners to him in terms of their relationship. It doesn't paint the Saiyan warrior in the best light, but there are actually a few reasons for why this is the case.
Goku's Grandpa Gohan Made Peace With His Death Long Ago
The main reason that Grandpa Gohan is never revived via the Dragon Balls is that he's made peace with his death and rather enjoys the afterlife. This was made clear to Goku when he fought Gohan during Fortuneteller Baba's tournament. Having apparently developed the same taste for beautiful women as his lecherous teacher Master Roshi, Gohan sees no reason to return to the land of the living with such lovely ladies surrounding him. Likewise, the filler finale of Dragon Ball gave Gohan the new role of bodyguard for Annin, which would logically keep him too to be revived long term with the Dragon Balls. Likewise, it's arguable whether the mystical dragon Shenron could even revive those who didn't want to come back, further complicating things.
It's worth mentioning that a someone retaining their body in the afterlife is extremely rare, with even Grandpa Gohan's assistance to Annin in the anime being utter filler and likely non-canon. As a result, Gohan may have long since lost his recognisable shape, making it difficult for Goku to ever find him if he went to visit him. This was Videl's explanation during the Buu Saga, as it would have been impossible for her to find Gohan if he had genuinely died. In other words, it's not Goku's laziness or lack of subtlety that keeps him from seeing Grandpa Gohan on a daily basis, but the reality that the old guy is long dead... and enjoying it.