Bad Astronomy: the Galactic Habitable Zone

A star has a certain luminocity, and as a consequence there is a region around that star beginning at distance x and ending at distance y that is neither too hot or too cold for earth-like temperatures to exist.
The greater the luminocity of a star, the greater the distance that habitable zone is from the star, and the wider that habitable zone is. This also applies to the galactic centre.

Lets consider a galactic centre luminocity of:
L*=1,000,000,000,000,000,000

As a consequence its galactic habitable zone begins at around ten thousand light years from the galactic centre with a temperature of 320K (46 degrees C) and extends outward to 13.674862 thousand light years at a temperature of 274K (0.85 degrees C).

Examining the habitable zone galactic map: Twenty thousand light years of the Norma Arm fall within the Galactic Habitable Zone along with two smaller regions: ten thousand light years, and two thousand light years. Thats about five hundred by five thousand stars or two point five million star systems in a shared habitable zone. It means that section of the Norma Arm will most likely develop interstellar civilization.

                                  Galactic Habitable Zone
                              Inner Limit        Outer Limit     Our Solar System
GSA**                       10,000ly         13,674.862ly     26,700ly +/-1300ly
Temperature (K)      320°K                274°K                       199°K

**Galactic Semimajor Axis

You are thinking what the hell, there is no way the temperature in our solar system has a temperature in space of 199°K, but our star has a hydrogen boundary formed by the ignition of the star with an Albedo of 0.9-1 so its interior is somewhere between 0°K-122°K not including our own Solar Luminocity effects...

Where are we?
We are about 13,000 light years beyond the galactic habitable zone. So if the habitable zone has earth like temperatures no matter where you are (beyond the habitable zone of individual stars) in any solar system within that habitable zone, it is practically oozing with the conditions for life. If we were in the habitable zone we would have life on Titain, Mars, the moons of Jupiter, even Pluto. And we wouldnt be the only ones enjoying warm weather. There are considered to be ten million stars within 3.2 light years of the galactic centre. So out there are million of stars in the galactic habitable zone straddling the spiral arms between us and the centre.

You wonder why Aliens are not contacting us? They live in the Galactic Habitable Zone. From their perspective the Galactic Habitable Zone is the only place to find life. You can literally travel from habitable planet X to habitable planet Y and its survivable... remember those starships with Agriculture farms? Yeah, them. They are sustainable technology for movement not just between Planets, but between Solar systems. All you need to do is hold in the Atmosphere and water, and be prepared to spend a million years travelling from solar system X to solar system Y.

The question is, why are we not in that habitable zone?