There is a nice thread going on. It's a nice read.
The major problem is a lot of legit players are frustrated because of
1. Botters, Spam bots, Dupers, ...
2. Complaining about this is as talking to a brick wall
I understand the current battle.net has his limitations. So fixing this would be unrealistic. But why doesn't blizzard talk about this? If they would post why they are unable to offer a cheat-free community there would be much less frustration, so we now what we are dealing with.
Other companies have done successful stuff to keep cheaters away from their old games. You can play old games like Quake 3 and there will be no cheaters (Punkbuster). You can play the old Counterstrike 1.6 and no cheaters (Valve Anti Cheat). Ok there are cheats avalaible from both these games, but the anti cheat gets updated frequently.
A lot more effort could be done to stop botting for example. Maybe it wasn't possible to stop the hacks & dupes. But maybe with some reasoning they could make it so that no chars would be viable for botting. For example: Make the Teleport skill weaker for example & make the game harder so that you need intelligence to play this game, so no "BOT" can play it.