Meh, I get the feeling why Bob's kids became estranged from him had a lot less to do with him and almost everything to do with Barb (and possibly Chris after he achieved internet infamy)
Barb's family explicitly hate her because of her horrible personality and backstabbing ways, so I wouldn't be surprised if Bob's kids had the same sentiments and avoided Barb at all costs, even if they still liked Bob.
The only one of Chris's siblings who we can definitely confirm as hating Bob is Cole.
Cole hates Bob, but Cole is also a notorious douchebag and mainly hates Chris out of a mix of projected hatred towards Barb and envy over the fact that Chris is a legend in internet culture (especially after PewDiePie and other mainstream e-celebs started talking about him) while he's pretty much a "literally who?" figure among anyone who isn't closely following Chris's antics.
Cole's only claims to fame or notoriety are the fact he's Chris's brother and for being the asshole hipster that gave Toy Story 3 a bad review.
We know next to nothing at all about Carol Chandler other than she has a government job somewhere, and David Chandler was already leaving the nest by the time Barb entered the picture and was likely in college and working on his professional life when Chris was a kid.
Notably, Dave Chandler did show up to Bob's funeral, so he couldn't have hated his father that much. Carol didn't show up, but she has a government job and we don't even know if she lives in the same state as the Chandlers. It may have been possible she wanted to say her goodbyes but couldn't due to distance or some other unknown factor.
Honestly, Barb is the main reason why Chris is so fucked up as a person and has no real family support to speak of.
Don't get me wrong, Bob was a shitty parent too, but his parental failings stemmed mostly a mix of from incompetence and old age while Barb was more directly malevolent and abusive.
Bob at least tried up to a point, while Barb only cared about herself and the hoard.