It doesn't have to be his ONLY motivation.
And why are you people so wildly against the idea pretending like he's coming back the day after condemning him to torture and death. Fuck, within a day of that Walt has lost everyone he loves. You don't think 9 months to look at the stark reality of what you have become and what you've helped happen all while looking at a death sentence that you can feel getting worse might change someone a teensy little bit? He's had a huge soft spot for that emo junkie for 2 years, he went all the way to wanting him dead for what, 2 days? And it's retarded to think that he might not maybe regret the decision to sentence someone he cared for to torture and death with MONTHS of time alone to think about it? Especially when he finds out the kid is still alive and living in hell rather than just killed within a day or two like you expected?
Yeah, that's ridiculous. It's so much more likely that he's just decided he's Rambo now and is there for revenge. 9 months later. It's not like they've given these characters any depth, surely Walter White has not changed as a character at all and thus we should think he never will. Right? He started the show as an evil meth kingpin right?
He's coming to save his fake son. You guys are gonna feel like assholes.
Or I'm way the fuck off base and will look like a total fuckwit. It would not be the first time.