We do not have tall buildings. The only large structure that can be seen from above is the Marcos monument in Ilocos and terrorists are welcome to target that.
We all get on the job late in the morning specially government employees, so at 8:45 there won't be sufficient people to kill (well, not even at 10 am!).
Fire fighters and police officers will do their utmost not to get to the spot in time. They will reach there just when everything is over, so there will be no casualties among them.
The national airline would surely have fouled up the terrorists plans by being delayed again or crash before even getting to the target due to mechanical troubles.
A Pinoy would not have used his cell phone to call home. He would've hit the terrorist with it over the head.
If a terrorist was living for one year in Manila he would've been robbed and molested so many times he would've given up and gone back to his home country a long time ago.
In Manila, the terrorists would not have gotten the flight manual, they would've had to pay for it.

You see... in Manila we are well prepared!