I actually think that's a good question. While you should never use your sense of smell as a definitive analytical tool, I see no problem in showing people another 'tool' they have in the analysis of a compound. If you make an ester out of some unknown chemicals, your sense of smell can save you a TON of time on the analysis. Just based upon the odor alone, you should be able to narrow down the list of possible esters that it could be. This makes analyzing your NMR and IR data a heck of a lot easier.