Please re-read LadyBug's reply. It sounds like she and I are married to the same guy.
I also am not as willing as others to let your husband off the hook and say "it's just the way he is." Too bad if it is. He can at least PRETEND to have an interest in his children's activities. They will remember his absences, believe me. I do not think you can expect him to be at every event or game -- not realistic - but he should want to be at some, especially a final choral concert or a signficant sports game, etc. He put the burden on you to tell him that concert was significant -- so from now on I'd be crystal clear that "This is the playoff game so it is important, and unrepeatable, so please be there" and "This is the final choral concert of the year and it is a huge event so you need to come--is that clear?"
Has your oldest child ever told him, "Dad, I really would like you to attend Event X and here is the flyer with the date and time"? You don't want to make a child responsible for a parent's behavior, ever, but if he just tunes you out when you try to tell him he needs to do these things -- he might actually listen if his child says, "This is important to me."
I do not think you are wrong to believe he should try to do at least some of the kids' activities. In fact, I would sit him down and talk (without the kids around and when he does NOT have any other things he "needs" to be doing) and say that he now will be responsible for taking a kid(s) to soccer every weekend, or every other weekend. He needs to be the principal parent for some activity - you have two kids and you should not be the sole person handling all their activities. If he does the eye roll, call him out: "You just rolled your eyes, and to me that says volumes. Your own children seem to bore you, frankly. You may not love soccer but neither do I. We don't go to these things because we love soccer but because our children will get the message that we care about their interests even if they are not our own personal interests."
Sorry, but dads like your husband make me angry -- and it sounds like you're angry too. Be sure you don't get wound up and angry (or tearful) when you talk to him because it sounds like he'd see that as emotional blackmail. But he is missing his kids' childhoods. Some men still have the "I'm the breadwinner and that's my job, so this other stuff is just insignificant" attitude. And yes, the kids will get used to assuming that mom is there for activities and dad just is not, and they'll get over it; they may not be hurt. But they will remember it, and possibly repeat it when they're adults.
My husband goes to our daughter's ballet performances, her orchestra and chorus performances, etc. No matter what the activity was he would go because SHE put work into it - if it's work in a sport or art in which he's not personally interested, that would not matter to him; he would go because she put effort into something, period. Can your husband get the idea that he should be there because of their effort, no matter what the event?
I really hope he wakes up soon. i know you must feel lonely when you're the only parent there for the kids at events, especially concerts or big games. Does he do other things with the kids that make him feel he has his own "kid time" so doesn't need to be at events and games?