I would tend to think that proper exposure is more important then proper development insofar as gaining an expressive print as the end result. The reason being with today's variable contrast materials we have the ability to alter contrast filtration to enable a expressive print from either a "flat" or "contrasty" negative. As other's have said, if it is not on the negative we have nothing to print. Most films have the ability to record greater luminance ranges then do the papers to print them.