First of all, the car is a tyre eater. How many times this year have we been waiting for a pit stop because the lap times were just abysmal?
But this should be no excuse for the strategy last weekend, because instead of a reaction to the worn out tyres the team sticks to their plan. As some wrote above, a further pit stop for options had been a good idea and if they considered this earlier in the race they could have shortened the 2nd and 3rd stint on the Primes.
Well, maybe they aren't capable of clairvoyance. But at least when they saw that JB will be eaten by the train behind him they could have pitted him. He was going to score 0 points anyway.
The contrast with Red Bull is immense in this regard. When Vettel pitted with something like 8 laps to go even I thought 'What's Red Bull doing? He's already 7th and who would pass him now?'. But Red Bull just crunched the numbers and took action. Instead, McLaren just stick to their plan made in lap 1 and despite Jenson pointing out several times during the race (also during the first half) that something seemed wrong at the rear of the car causing excessive degradation, they still kept their foot in with an effective 1 stop strategy. Tiresome and painful to watch.