@ali00447493,
Well, they kinda sound like jerks.
But maybe I'm wrong - I don't know anything about them beyond what you've mentioned.
However, the other thing is, people's lives change when they become couples and when they become parents. And they don't always realize the implications of that. I have had single friends ask me about - hey, let's get dinner - and I've asked them, can my husband tag along (we don't have any kids)? They aren't always so enthusiastic about saying yes. I try to be sensitive to this and suggest a second get-together where it's just us. But I will admit I don't always pick up on this, and I'm not even newly married. I ask if my husband can come along not because I don't want to have an intimate conversation or that we're joined at the hip - it's more that I bet my friend would like my husband, too. That's the motivation there (at least it is for me); it's nothing sinister.
Another thing with parents, particularly new parents, is that their children are a huge part of their life and of the conversation. It's not just doting (Oh my God he gurgled something that sounded like the Gettysburg Address and he's only a month old!). It's more like - this is how they spend their time now. If something was taking up 75 - 95% or more of your time, it would probably be your main topic of conversation as well.
I, too, am self-employed and work from home, and it can be a struggle to have a semi-social life. A lot of our social lives also revolve around work. So instead of trying to get the gang together, or trying to go to a club (new parents will be too tired, and newlyweds won't want to go without their spouses), try something more one on one and low key.
Are there museums in your area that you've never gone to? Waterfront or beach? A neat new restaurant?
Think differently. They have changed and, by definition, their relationship with you will change, too. I know you didn't sign on for this, but this is the way of the world. You can either adapt your going out/socializing style to the group (because you are in the minority now, and you are not going to change their new culture all by yourself), or cultivate new pals.