The problem is not the use of advanced antibiotics to treat serious diseases when no alternatives are ready, but rather, using high tech ABs when traditional antibiotics would suffice; even moreso, using antibiotics when none are necessary at all (most colds, most sinusitis cases, minor skin infections, undiagnosed abdominal pain, cough, viral infections, etc.). I have spent alot of time explaining to patients why they don't need antibiotics for a sore throat that is 90% plus due to a virus.
Of course every patient and illness is unique. But the available evidence calls for far less antibiotic use than is standard practice today. And multi-drug-resistant strains are the result, ranging from staph to TB.