people would spend more time building their careers when their kids are really young. Then, when their kids get a bit older, they would have more flexibility with their time and money to spend quality time with their family. It's a strategy that has worked well for many... it means you sacrifice a lot of your hobbies/interests for a season, but it's a sacrifice worth making.
One significant benefit of working a lot when you're young is that the extra knowledge and experience you gain early in your career stays with you (and is useful) for decades. It's a 1 + 1 = 3 kind of thing....
I think we can learn a lot by looking at our Prophet. He's worked long hours his entire life. He became great. He made a difference. I don't think anyone would claim he neglected his family, yet he wasn't around much. That's just the reality. He has 10 kids and he wasn't around all that much.
There isn't something sacred about being home by 5:30 - and I'd argue that for some, they would be much better off not being home at 5:30 (at least for a season).