Pharmaceutical industries have not developed much in the way of new antibiotics for a long time. There are a number of factors, most due to the problems of profit. But not always in the negative ways that you think.
Physicians are taught to not use antibiotics liberally, but only when necessary, and to use the most tried and true, and least expensive antibiotics first. Antibiotics may also seem to be the answer to sudden epidemics. Take the E.coli outbreak in Europe that is occurring now. We often treat E.coli bladder infections, but with these E.coli, they overwhelm one's systems so much that antibiotics would cause massive toxin release and actually worsen the patient's condition.
Yet we do need some new antibiotics to help fight emerging infections, or the growing resistance some common bacteria are showing. Congress has had to weigh in on the situation with a proposal to boost the development of new antibiotics. We may see some progress, but these studies are very highly regulated, expensive, and difficult to do. So it doesn't look like you'll have any new ones on your shelf very soon.