In the chat room, Gilles linked to a very interesting article about the military shortcomings of the Empire's strategic decisions when attacking the rebel base on Hoth.
It points out (correctly) that Vader missed several opportunities to slaughter the rebels (e.g., when escaping through "their shield’s chokepoint" or when the shield generator was down, by bombarding them from space with his fleet).
It says:
[..] Vader is now clear to destroy the Rebel base, and the escaping Rebel ships, with a punishing Star Destroyer bombardment. Presumably, if the Rebels are abandoning their generator, they’re also abandoning the Ion Cannon that protects the evacuation.
[..]
Only Vader can’t bombard the base: He’s in it. For reasons that never get explained — and can’t be justified militarily — Vader joins the Stormtrooper assault on the base. So much for his major weapon against the Rebels, and the primary reason for ordering the Walkers to invade and destroy the generator. Once Vader opts to bring down the shield and lead the invasion, he’s lost the battle.
(emphasis mine)
However, it was my impression that Vader's ultimate goal (which he did fail to accomplish) was to capture and turn Luke Skywalker, while destroying the rebels was a secondary (albeit important) goal. Although I admit, that I do not recall if he was aware of Luke's identity at that particular moment. But he was certainly obsessed with finding some particular rebels.
Now, given these priorities, were his strategies really as horrible as depicted in the linked article? And is this characterisation of his priorities accurate?
After all, a brute-force attack to simply kill everything on (and escaping from) Hoth would also kill his "high value targets". This would also explain why they didn't simply shoot down (or at least try to shoot down) the escaping transporters and why Vader intended the attack to be stealthy rather than brute-force-y.