If I/we continually put forth a good product, and then some idiot club owner decides to fill my band's slot with someone else because I wasn't there for one show, then he can go screw himself. If you guys bow to guys like that all the time, I'm sorry. What a mess.
However, I would argue that not one bass player on this forum is THAT important. (I know I'm not). Again, as I have said 100 times, as long as the band plays the right songs, nobody cares if it's me or a sub standing there..... not the club owner, not the staff, and certainly not the audience. (They care about that ALMOST as much as they care what rig I am playing through or which bass I play.... which is none at all.) If the club owner DOES care, then he is someone I don't have to work with. If you do, that's your problem. (But unless you give me a specific instance, I don't believe that would happen. No club owner is going to walk up to the band at the end of the night and say "How DARE you come in here without Two Fingers! Consider this your last show!" Ha! Fat chance.)
The short version is that getting a sub for a gig is NOT LETTING ANYONE DOWN. It's not screwing the staff, the owner, or the audience (or even your band mates for that matter). And you have to be carrying around a metric ton of self importance to think you are singly that important. You just aren't. It's ego check time for some people I guess.
I don't know. I guess the older I get (41) the more I just learn to not sweat things that really just are not that big a deal. Grownups where I come from tend to roll with it rather than getting all bound up over trivial stuff. If one of your band mates needs to take a night off on the night of a previously scheduled gig, I would hope you would act like grownups, round up set lists with keys, go play the show, and have a good time. But I guess that's a foreign concept to some. I certainly am in the minority on this one it seems. Oh well. Enjoy your rigid business commitments..... or bar bands. I prefer to play in the latter.