My guess is that your husband's job is a busy one -- and that it is full almost all the time, and then highly stressful and even more time-consuming in spurts. I also assume it was like this before your son was born ?
The fact that he has a good job allows you the ability to stay home, rather than pay a babysitter and work yourself. There are lots of moms in this world who don't have the choices you have, so while you have a concern about his time at home (or lack of it), there are other moms who would be very jealous of the gift he's given you by having such a good job and income.
When he gets home, how does he spend his time ? Does he turn on the TV and ignore you and your son, or does he then take the time to hold the little guy and chat with you, and participate in family life ?
When my kids were little, 6 months and even less, I was a working mom, with a fairly high pressure job, and my husband is the one who picked the girls up at daycare. He got the stories of what they did today, and the "fun stuff", and by the time I got home, most of that had been digested. So I got the bedtime chores. Sometimes I really wished I got home first, so I could have the time to chat with the babysitter and hear about the day, but he usually filled me in.
One of the things that can easily get lost when there are wee ones in the house, is the, "Hi Hon, How was your day?" kind of thing -- when you both worked, you probably both shared the ups and downs of the days together after getting home. With only him working, and with you worrying about how much time or how little time he is spending with his son, are you remembering to ask him about HIS day, and help him unwind a little. Who cares if he talks to you while holding his son ? The little guy will be soaking up daddy time at this point, listening to big people words, and learning language while Dad holds him and talks to you.
And, frankly, after a stressful day at work, baby-holding can be a wonderful release-- because at least for now, all your son's problems are pretty much confined to the house. When he's in school and the problems are "out there" it's a whole lot harder. So, at this point, ask about his day, get info from him to affirm your relationship to each other every day, and then share your day, which, of course, includes the little successes and new skills your son has accomplished. Remember that what is most important for a healthy child is that his parents have a healthy relationship. and, yes, Dad is missing out on so much of his son's life, but someone has to bring home the bacon . . . and if you want to eat, and you want a happy husband, he needs to be using his talents and skills, too, and my guess is that he really loves his job, draining as it can be at times. As long as he is involved with his son when he is home, that's what's mnost important.