The SS = Idiots

Did they want the bridge destroyed or not? If they did, then they have an unusual way of going about it, considering they take no action after being informed it's still up.

How exactly, did the conversation amongst the SS go after Kreuger's messenger arrived with news that the bridge still stood?

Lieutenant: The bridge you wanted destroyed hasn't been destroyed!
Gerlach: Why, that calls for absolutely no action whatsoever! Destroying that bridge is so important to the war effort that we must make absolutely no move to hasten its destruction, sit on our butts, and kill Major Kreuger if he ever shows his face, because assigning blame for the botched mission instead of seeing to it that it gets done is clearly the only logical course of action!

I just can't wrap my head around the logical fallacy that they want the bridge blown up so badly that they're not going to blow it up. The only way this makes sense is if they changed motivation behind the scenes halfway through and then forgot to tell Kreuger about it.

Did they just not have the right explosives, and know it couldn't be done, but felt they still had to make the wasted effort for appearance's sake, with Kreuger set up to fail so they'd have someone to blame? Not only are the SS dicks, they're idiots, too.

"I mean, really, how many times will you look under Jabba's manboobs?"