It is bollocks if you're being made to feel that your being paid is unfair on someone else, but that's a different question to the OP's point
The vast majority of people we're talking about here are not pros, and those who are - like professionals in every field at present - need to recognise that the economy is changing. Venues that go under now will not start up again, in a year's time they'll be flats or corner shops. A little bit of give and take, in for example the scenario in the first post, far from being an existential threat to the livelihood of musicians, will help protect the future of live music as a whole