You're not in my band...............
Sorry about your situation, but like another said, it might be time to spread out a little.
The thing I noticed about guys who do the multiple band thing is that they tend to take their musical bliss into their own hands. Whether it's more money, more gigs, a chance to write, a chance to play another instrument, etc. they tend search that out and will play in multiple projects, or hop from one to another to meet those needs. A common example is one that makes money and another that is a creative outlet.
It's certainly a challenge dealing with folks with multiple priorities, but that's a part of dealing with adults with responsibilities. If it's not another band, it's a job, business, kids, another hobby, etc. Of course it's great to have a solid player who commits to your band, and makes it your priority, but in reality, lots of bands want those great players and they have other opportunities to pick from to fill their calendar.
On the flip side, there's lots of positives to it as well. Because you work with multi-band guys, they shouldn't have a problem with you finding other work to fill your calendar. If they can't make a gig, they have a better chance of finding a sub for them. Since they are playing out, you can tap into their network for gigs. If your band isn't their priority, there's no reason you can't make it yours. The others may be relieved for you to take the reigns. And if you need to replace folks, so be it. One of the nice things about the multi-band guys is that they tend to handle being replaced a whole lot better. I prefer to work with multi-band guys for these reasons, and because I'm not solely responsible for their musical satisfaction and keeping their calendar filled. A whole lot less pressure for me. Money grubbers could be difficult to work with, but the positive is that it is easy to motivate them because you know what it is and it's tangible. "Creativity" and "musical expression" and much harder to quantify and motivate, IMO.
There's certainly some negatives in the situation, but there are positives as well. You just have to find them and exploit them.