Somehow they all use she/her pronouns or a feminine voice. I don’t have a firm conclusion on this yet - I just think this is a very odd trend. 

Will be added to as I find more or as people suggest more.

Cortana, from Microsoft. Source:

Ava, from Ex Machina. Source:

Siri, from Apple. Although I guess it’s more her than her creators? Unclear. Source: