Actually, maybe this behavior is a good thing (if not outright intended)?
I don't know about other people, but the few times where i'd be using a ruler overlay on side-by-side map comments would be :
-Times like this, where i want to know a Heavy's range but there's something else i've commented nearby, so the ability to distinguish between the two is slightly useful;
-Whenever i'm planning to attack a cave outpost or hack its terminal using cloaking/long range weapons (and i've commented every bot inside), and i don't feel like it ever bothered me before. If anything, i'm surprised i didn't notice it then, since this scenario happens far more often.