government funded shelters

Private animal shelters often are built near public shelters to do the job that the tax-payer funded shelter is not. They literally rescue dogs from the public shelter. Why is more not expected from a government run shelter? Why do citizens pay for two shelters - one with their taxes and the other with their donations (and hearts)? And why, pray tell, do we allow this to go on?

Private animal shelters often are built near public shelters to do the job that the tax-payer funded shelter is not. They literally rescue dogs from the public shelter. Why is more not expected from a government run shelter? Why do citizens pay for two shelters - one with their taxes and the other with their donations (and hearts)? And why, pray tell, do we allow this to go on?