I did spend a lot of time with my children in their earliest days because it was the right thing to do, but I don't feel either they or I particularly gained from it (than if I'd spent a bit less, say). Do I feel the time I spend with them now they're older pays serious dividend for their futures? Absolutely.
I own a company and can spend an above average amount of time with my children.. but are companies or the government going to support the majority of parents spending prolonged periods of times with older children? Sadly I can't see it happening, but I think that's a more important task than having two parents on tap for a newborn. All purely IMHO, of course.