Definitely projecting, then. 
But we all do that.
I just know how much having small toddlers and breast fed babies affected my own social life. But I also had a husband that went out occasionally until 4am.
I also left him on his own with the kids at weekends whilst I went to work (we weren't doing a reno). So he played an equal part in the child raising.
My social life was still shit.
The division of responsibility in a relationship is something for each couple to work out - and yes, so is the division of social time.
It looks as though work and a reno is the dh's 'job' in this relationship, and the childbirth and rearing is the op's. both are ft.
I don't see that it's a big deal for the dh to go out and get back late unless it's tooooooooooo regular an occurrence - he does need to blow off steam once in a while. He shouldn't be stopped from doing that just because the op can't do it herself at the moment. So they both need to work out how/ when she's going to get her 'rest' from her ft job.
Of course, if he's being a cock, then whatever. But it looks like a perfectly normal 'everybody knackered and I can't get drunk myself and I've just realised I haven't been able to for four years' hormonal rage. Yes, I've been there. But we all make choices about the division of responsibility, and they all have pros and cons.
I'm not a huge fan of the 'you woman, you look after the babies' role, because that leads to inevitable problems (when the reno is finished, for example) - and that's why I worked weekends and left him with the kids from Friday until Sunday night - but sometimes you need the rage in order to re-evaluate and rethink your division of responsibility.
It doesn't sound like the dh is slacking in terms of his overall commitment to what the couple are committed to providing, but it sounds as though the Dw has just realised that she has fallen into the 'easy' trap. Me woman, me child carer. It does take some effort on both the dh and ds's part to look at whether that works in the longer term. For her, as well as the family.
It doesn't necessarily mean that he's an arse. He might be, but it doesn't follow.