In your shell script, you executing the
osascript -e 'Tell application "Terminal" to do script "osascript ~/Scripts/reset_simulator.applescript"'
what really opens an new Terminal.app window.
Have you some special reason to open an new terminal window? Why just not running the
osascript ~/Scripts/reset_simulator.applescript
from your shell script and in the current window.
But if you want such thing (sounds to me strange) always can use the next:
osascript -e 'Tell application "Terminal" to do script "osascript ~/Scripts/reset_simulator.applescript;exit"' #note the "exit" here ---------------------------------------------------------------------------------^^^^^
and change the Preferences to "close window" when the shell exits.
Reading your comments above, sounds me than you want run some applescript in the "background".
So you can do the next:
a.) from your shell script
osascript ~/Scripts/reset_simulator.applescript &
2.) if you want still open the another terminal window
osascript -e 'Tell application "Terminal" to do script "osascript ~/Scripts/reset_simulator.applescript&exit"' #note the & here --------------------------------------------------------------------------------------^