But seriously, if they are not showing up much, just tell them that is why you are switching to a new team. They are adults - they shouldn't hold it against you. I've known a lot of people that have switched teams and they still have a lot of friends on their old teams.
Teams and riders know when a team is not very involved. Some admit it readily, some don't, but if you want to have a more involved team and teammates, tender your resignation and switch teams.
Friends will stay friends, and friendly riders stay friendly riders. Those that hold it against you probably have other problems anyway and you don't want to have to deal with them.
I've raced for a couple teams and still say hi and stuff at races (they fall under "friendly riders"). I don't hang out with them when not at a race but we don't hate each other or anything. They're good guys and so they act like good guys. My former teammates (moved away etc) who are friends are really my friends - many of them attending my recent wedding, a couple as my groomsmen/bestman. I wanted more of them to be groomsmen but I couldn't have a 10 person wedding party.
Quit the team, keep in touch with whatever friends you have there, and join another friendly team that happens to do more team rides etc.
I dunno. I have lots of sunk costs with the kit...
See if someone on the team wants to buy some. You'll lose money on it but if you really want to change teams...
The other thing is that most teams need a leader of some sort, someone to get things going, goad people to get out and ride, etc etc. If you feel like being that person, you can make the team a little more to your liking. I basically got into that same position for a while, like 15 years. It involves more work and effort and dealing with stupid little things like soap opera ego things but overall it can be pretty rewarding.
If you don't feel like it, then you should talk to whoever should be doing it. Or volunteer to help.
Ultimately, if the riders on the team are not totally into racing, then it's a dead end. You can't force them to participate, you can only make them want to participate. I think many teams lose 80% of their members by the time racing starts. Not in a literal sense, just that 80% of the racers do a race or three and then sort of disappear. They reappear when it's a team meeting or a picnic or the mid-winter meeting to order next year's kit.