One word. Shyte.
Having drawn you in, building the characters, really quite well, the film effectively ends with the fight with robots in the bog.
"We can't just do a clever funny well-scripted film about mates meeting up after many years, first 45 mins... spot on. No, we have to pander to morons by trying to shock and 'entertain' and losing all the good work done in the first 45-60 mins."
Dross.
