I guess a couple of degrees really don't matter- but 5 degrees would, especially if it drops near the beginning of the mash. It's not so much a sense of pride, but of knowing how the beer should turn out based on mash thickness and temperature of the mash. My system holds the temperature. I like it because I can easily calculate my mashout temps and sparge temps, since I know the temp of my grainbed without even opening the MLT.
It's the same thing with efficiency. Say I get 75% efficiency each and every time, and make great beer. Why should someone who gets 88% efficiency think that they are "better" than I am with my system? It's just a number that helps us dial in our recipes. It's not better or worse- it's a number. In fact, some authorities have written than a super high efficiency might be detrimental to the flavor profile of the beer (I don't think that would be an issue with homebrewers). It's just a way to talk about our systems (all are a bit differerent) and to compare what works for us.