An incident

An incident happened this afternoon,which had nothing to do with trans but left me with a nasty taste in the mouth about human nature.
I was waiting to be served at the kiosk section of a supermarket.
There were three posiions,one for sales and two for customer sevice with quite a rush at the sales section.A woman asked if the customer service girl would mind serving her and when she did a chap who was waiting rushed forward saying he was there first.
Fair enough,he was but his attitude was of someone spoiling for a fight.The girl was half way through the sale so the chap started swearing at her,at first mildly then F word threatening.
All the customers just pretended it wasn't happening so me 5 foot 7 in my heels asked if he would moderate his language.The rest of the customers then pretended that I wasn't there either.
By this time I was just waiting for him to threaten me with a transphobic comment and I would have called the police and got the foul mouthed git arrested.
Then the security guard came along and asked him to leave the store for threatening language to a member of staff.
My question is if the public can stand back while a girl gets this type of abuse what hope is there for us if someone decides to give us a kicking?
The chap concerned was about six foot three and built like a brick outhouse but why was it only me who was prepared to take him on?