I have heard others say this and I don't get it, I have fought and killed 25+ dragons in my 130 hours and believe it or not (level 38), I have enjoyed every one of the battles and this is on Expert ! I think the catch is, you need to explore on foot, fast travelling here and there all the time doesn't help, try picking a point on the other side of the map and walk there, I know it sounds shocking but its a great way to play! Also if you are after Dragon Shouts pick all the highest points on the map and go there, I have found most word walls are up high on peaks, if you hadn't already noticed that is! Obviously where there are word walls in the open there are Dragons so maybe try that?
If Dragons arn't noticing you just get their attention, a few arrows does the trick, but like I said I haven't really had this problem, once the epic Dragon music starts I know I am in for a tough time

Btw I just ran into my first Elder Dragon at level 38 and Wow was he a surprise, killed me 3 times before I learnt to hide and then whallop him with Ebony Arrows!