Why doesn't current flow in the other loop?
In order for current to flow in the base of the transistor, there must be about 0.7 V (maybe 0.5 to 0.6 V for a small current) between the base and emitter.

But you have a short circuit between the base and emitter of the transistor.

If you had 0.7 V (or even 0.1 V) between the base and emitter, then in theory an infinite current would flow through that short circuit. (Practically it would be 10's of A until the wire melted) But your supply can't provide infinite current (or even 10's of A) because of the 1 kohm resistor.