Different acids have different flavors and the majority of the acids found in grapes is from tartaric acid - so adding that acid will not fundamentally alter the flavor. The addition of other acids not found in grapes , or found only in tiny quantities will likely alter the flavor. I presume then that the idea of using tartaric rather than either a blend of acids is to inhibit unpredictable changes in flavor.
The issue is that certain acids can impart unwanted (normally) flavors to a wine. Some protect the wine, and some have little impact on the wine except in large, disproportionate quantities. Most discussions of wine acids are aimed at telling us why acids are good up to a point but those discussions are aimed at consumers not makers. Jack Keller's is one of the few I found that discusses the plusses and minuses of the various acids. There a probably others if you look hard enough, and in fact several threads exist on this forum. Take some time and read up so that you aren't taken by surprise by an act that you take that seems harmless but later on ruins the flavor of your wine.