I destroyed the base becuase TIM asked me to preserve it. Nothing more. Reverse Psychology wouldn't have worked because I would have destroyed it anyways. Cerberus is fully welcome to whatever they can find in the wreckage, however. Payment for life.
Those that say that Cerberus would have to wait until after the War's End to do anything are WRONG!
Cerberus doesn't think like that, and IMMEDIATELY start working against Shepard. Evidence: Mars. (Slight Spoilers follow)
TIM has the Data from the Mars Prothean site deleted to prevent ANYONE, and especially SHEPARD, from using it, so that HE, and HE ALONE, has the usage of that data. It's only the sacrifice of one of Shepard's Squad (to serious Injury) that prevents TIM from succeeding. This comes from EA video, not from the leaked Beta.
Neither TIM nor Cerberus can be trusted, and they both have proven this many times, In ME 1, in ME 2, in the comics, and in the books.
On the Topic of there being no choice: This is blatantly false. There are ALWAYS other choices. These other options don't have to be obvious, not do they have to be good ones, but they are there. Shepard could have suicided (had the game allowed it) rather than go on IS an option. For Example: Morrigan from Dragon Age Origins(paraphrased):
"You can always run away, and let the Darkspawn overrun Ferelden."
Alistair: You call THAT a choice?!
Morrigan: It is a choice. I never said it was a good one.
Think on it. For Mass Effect, All paths lead to the same place, it is the deeds done, and the deeds not done, that determine your fate.