See in the above picture, the dar would move from [18,18] to [19,18] for a short period of time then to [19,17]. Anyone watching would know exactly where you are and be able to guess your heading pretty accurately.

Exactly. You might as well broadcast your location & vector on CH200

And that's not all. The intercepting player can also look for additional information. MA activity seems to be random and chaotic, but to a large degree it is not. Players have motives, they have a reason to be at a specific point, they do have a plan, a target.
Ask yourself: Where might he had taken off? Bomber pilots prefer high altitude bases. In Jayhawks example, you would trace the rout back to see if there is such a base where he might have taken off from. From that altitude and the distance/time he already base covered, you can make a educated guess about his cruising altitude (keeping in mind there are some "customary" flight levels players tend to follow). Watch the map where he might be going: Is there any big battle in the direction of his general heading? Is he going to the strats? Or will he try for that CV of yours (very unlikely if he took off more than 2 sectors to the rear). Or is he simply flying for score and will drop half a dozen town centers for points?
Also quite a number of buff players do dodge the dar circles, but ignore the fact the base town's have a alarm range all of their own. You might not show on the base radar, but you make the town flash. Combined with darbar you are giving your enemy a very good hit on your exact location.
Of course you don't have to play that way. It's probably pretty boring for most folks. But then, don't be surprised when somebody shows up to kill your bombers, or (on the other side of the coin), don't exclaim "where did all the bombers suddenly came from?" when you find your furballin base obliterated by a 20k bomber raid

Anecdote: Once I was accused for using a spy account when I "magically found" a 10+ formations bomber raid about 30 minutes after takeoff at 20k. I almost fell of my chair.
