You only see a small part of the bigger picture. Not that I see the whole of it, but evidently my view grasps a larger part of it. The Saudis are the US puppets, all their cash reserves are in the US dollars and held by the US funds. Everyone is free to decide for themselves how "sovereign" their funds actually are thereby, but the events now transpiring (e.g. lifting the 40 years old ban on oil exports) leave little-to-no illusion that the US is interested in bringing the price of oil as low as possible. Why they are doing this seems to be pretty evident too. So the Saudis will pump as long as Uncle Sam deems it beneficial...
For himself, not the Saudi royal family, of course
This is relevant to my point:
http://money.cnn.com/2015/12/28/investing/saudi-arabia-budget-oil-opec/index.html?sr=fbmoney122815saudi-arabia-budget-oil-opec0553PMVODtopLink&linkId=19946097
Saudi Arabia is being hurt by low oil prices, but in their calculation, they have determined they are better off long term by flooding out the higher cost producers now. They will respond rationally to the economics of the situation though. They can only skate on their cash reserves for so long. Eventually, they have to let the price of oil rise or start borrowing, and the capital markets will not be kind to a country that frittered away a huge reserve and is a desperate borrower, and the ratings agencies have already started to sound that warning bell, which is why I think Saudi Arabia is starting to curb energy subsidies and take other cost saving measures.