Not to speak for Alex but he's said something in the past that relates to this AI behavior: it's better for the AI to be too passive than too aggressive. Though you may be frustrated at a ship not capitalizing on obvious opportunities (in this case, being too conservative with Burn Drive), you would be irate if the AI constantly killed your ships by using it too aggressively. Not saying that the behavior can't be improved but he's right.
I do agree that the AI cancels Burn Drive too much but I'd much rather it err on the side of playing it safe than suiciding itself. If Aggressive/Reckless doesn't make ships more prone to Burn Drive to pursue, it should, though I haven't really tested it.