If we added up the number of pages in the book where Bobby Bishop appears, and figured out the percentage of those pages that occur in the whole novel, we think that percentage would be about 2%. And we're being generous.
In his strikingly few appearances in the novel, we don't see him being kind or nurturing either. He's always getting into trouble and doing nothing about it, so that his sixteen-year-old daughter's only choice is to put her own safety at risk to save him.
So, yeah, he's completely oblivious to what Kat needs or wants—like a stable home and a close family—but she doesn't exactly come out and tell him either. We get the feeling that the death of Kat's mother/Bobby's wife has put some space between these two characters.
But again, all that drama goes unsaid. Bobby and his family simply aren't the sharing types. Probably because they're thieves, and when thieves talk too much, they can end up in jail.
Simon may be an essential part of the crew—every heist crew needs a tech whiz—but he's basically a non-character. We can sum Simon up in four bullet points.
The "distant parents" part is key for our discussion here, because that's something that all the crewmembers have in common. Didn't you notice that these kids have to do pretty much everything for themselves? Of course, the seemingly bottomless bank accounts of Simon's distant parents definitely help.
Uncle Eddie is Kat's mother's brother, but he's just as unhelpful as Kat's dad is. Lack of outright affection for one's kin must run in the family, though we're given very few clues to go on as to the family's complicated past. At least Uncle Eddie makes some yummy borscht and keeps the kids fed.
However, he is completely unconcerned about Taccone and what he might do to Kat's dad. We only see Kat's point of view on this issue, but she sarcastically remarks to her dad, "Uncle Eddie always has your best interest in mind" (21.27). Yep, there's some history here, but we have no idea what the specifics are.
What we do know is that by forbidding Kat to do anything about Taccone, Uncle Eddie prompts Kat to work even harder to save her father. Could that have been his plan the entire time? Maybe our guy Eddie is smarter and more nurturing than we thought.