Stellar Nebulae and angular momentum

[mateomy]

Maybe this is a simple question but, all the stuff I've been reading so far keeps talking about protostars and their angular momentum being a consequence of the surrounding nebula. Why do they inherit that in the first place? Is is just a consequence of the gravitational collapse?

 

[Drakkith]

In a collapsing gas cloud it is practically impossible for it not to have net angular momentum during/after the collapse.

 

[Martinaston]

It has to be due to an outside influance, so all nebule must be linked in some way.

 

[Drakkith]

It has to be due to an outside influance, so all nebule must be linked in some way.

What is your justification for this?