Either that, or xenomorphs are just naturally attracted to wearing such garments themselves.... (Which is not that out of character... I've met plenty of "monsters" that wore them to cocktail parties)

"[The audiance] will populate the darkness with more horrors than all the horror writers in Hollywood could think of. If you make the screen dark enough, the mind's eye will read anything into it you want! We're great ones for the dark patches." -VAL LEWTON