Mannerisms in public transports

The Lady with her hubby just boarding the bus went in the front only to find the whole bus occupied and no place left to be seated. One guy promptly stood up giving his place tothe lady who obliged while being seated. The next seat got vacant besides the Lady and the Lady calls up her hubby to be seated whos quite behind a couple of people. He comes and occupies the seat with the man who initially gave the his seat still standing. This is one incidence of many which can be picked to discuss the topic.
The etiquettes tell us to give place to women passengers, pregnant ladies and elderly persons on priority. This was more often seen implemented by many over the years. The other half of the same etiquette statement also implies to the ladies, that lady is also to give the seat to a pregnant lady or aged person.
In my life till now I havent witnessed a single incident where in the ladies have actually done this. The reactions follow..now we dont often see even the men giving place to women. One has to be equally worthy to give and receive the honours.
Another unsaid aspect of etiquettes for public transport, I have tried to highlight in the example above is the right of the person doing the honours. when the adjacent seat vacates, is the person who gave the seat to the woman not rightfully entitled to get? is he not more eligible than her husband who has no merits except being her husband?
I feel it should be this way. The man giving seat is to be given the vacant seat ahead of her husband. This positive gesture given back to the one following the etiquettes would encourage him. Selfless thought on behalf of woman is required which is what I feel along with the same from men.