There's always the third option of Bottas being allowed to pass with Massa backing up the pack to allow the Finn to create a good lead, after all it's a team sport, so why not sacrifice one driver for the sake of the team. But it all became a moot point with Williams being so terrible in the wet and of course the super late call for inters allowing Vettel to snatch a podium!
The fact that you think Williams had the performance advantage to be able to hold Hamilton & Rosberg back just shows how out of touch you are, The only reason Bottas was able to hold onto P2 for so long was because of the tow and DRS he was getting from Massa, meaning Hamilton couldn't get close enough to Bottas because Hamilton had significantly further distance to catch up and overtake in.
As for the "sacrifice" point, it's pointless to risk a strategy like that to gain a potential 4 extra points when Bottas could have a car failure and they'd lose out massively, he could have a spin and lose out massively, it could rain and they'd lose out massively. The only time you do that is when the difference between the two cars is tyre compound, one is significantly faster than the other or if it is for the championship. They aren't in contention for the championship, they aren't under threat from Red Bull, they can't challenge Ferrari this season so the team made the right decision to hold station and race, hold onto P1 and P2 rather than risk big point losses for a miniscule chance of winning.
There you go, you are speculating, just as the rest of us are.
So, yeah, I'm for real, thanks for asking! 
I'm not speculating, I'm giving you a logical, common sense, real world answer that a monkey could understand.