cross coupled of two transistor will give negaive impedance therefore negative gm, or transconductance.
it will compensate for loss of inductor and resistor therefore commonly used in oscillator design.
now why the same configuration used in a latch or storage element?
so, you want the same type of oscillation happen in a latch?
The classic astable multivibrator has two cross coupled transistors. It is based on the RS flip flop which is a storage element. The concept is that a bias (small signal) causes a change of state. It is stable indefinitely, until bias is applied to the opposite transistor.
So the astable multivibrator is set up to apply self-bias back and forth. The capacitors cause it to oscillate between changes of state. You could call it an RS flip flop which was tampered with so it is unstable.