Why Skyfall stinks

Warning: Spoilers

I was irritated when the IT genius at MI5 received a laptop from a known computer hacker who has just previously taken over the MI5 computers to turn on the gas and blow up the building and as their first response plug it directly into the mainframe.  Dammit, there would be anti-virus rules stopping agents doing that with any laptop, including their own: for anything suspicious there would be a clean room with no external data access.

That became less important,  though, when I realised that villain's fiendish plot to have himself captured so that his laptop would be plugged into the mainframe so he could escape and run through the undercroft to emerge in front of the hearing room where M was being grilled so that he could run in and shoot M was merely a way to fill up an hour of screen time, given that if he'd done none of it he could have simply walked up to the front of the hearing room and run in and shot M just as efficiently, or not, given that he botched the only bit that actually had to be done right.  Why didn't he run in with a gang of five or ten, or thrown in a bomb, or put a bomb underneath the hearing room, or shoot M while she was going in or out?  Bearing in mind, of course, that he couldn't possibly have known in advance the day and the time when M was going to be had up for interrogation, or arranged for it to be timed to coincide with the inplugging of the laptop...

Which led to the real flaw in the whole thing, the underlying system, which was that everybody at every given moment had to have been been watching the film up to that point.  Perhaps the best example comes towards the eagerly-awaited end where villain sees torchlight across the moors. Aha, he says, there goes Judi Dench. I'll go and chase her while you kill Bond. How does he know it's M ? He knows that Bond and M were in the house, he doesn't know there's an escape tunnel - why wouldn't it be a neighbour, or a hiker?  Or Bond? He knows because we know.  Villain pursues Dench and ghillie (who would have known better than to use unshaded torch, one would have thought) to the abandoned chapel, and just walks in.  Villain knows fugitives were at one point armed, he doesn't know they've put their weapons down, why doesn't he take precautions?  Because we know they aren't armed (for no particularly good reason) and if we know it he knows it.

Returning to minor irritations,
In the fight at the end, twelve thugs walk down to the house (why didn't they drive down?) (and cluster exactly in the only spot where Bond can machinegun them from the Lotus) and are all shot or blown up (by booby traps that would not be sufficiently lethal),
at which point the helicopter lands and lets another nine thugs and villain out - so why didn't they time those to coincide and provide 21 thugs?
so the next nine thugs go in and seven are killed, so the helicopter shoots up the house - so why didn't they do that as step 1, before having any thugs arrive at all? Or have the helicopter drop off a large bomb?
so Bond downs the helicopter, leaving the villain and two remaining thugs, kills one thug and runs off across the ice; other thug, having been told to kill Bond, holds gun on him but does not shoot but instead walks upclose enough for bond to grab the gun (AGAIN for the third time in the movie) and save himself.....

The rooftop chase and the earthmover/train bit were ok, but we'd seen them in the trailer.

And all the reviewers raved about it.  Can't understand it.