Why is it acceptable? Because with the current system, we have no choice.
Market forces mean that no-one stays as a career FI anymore unless they have an income from elsewhere and we won't allow enthusiastic "amateurs" to do the job.
Daft I know, but until the wages increase to a level that is liveable and GA flying actually becomes something to aspire to, rather than as a stepping stone to big shiny and boring airline flying, then nothing will change and we'll just have to muddle along as we are.