From a male point of view here
Tradition works both ways, many posts on here about a man expected to pay on a first date comes to mind....,,,,lots of ladies here still want that and expect it, others don't
I agree the EA has it wrong regarding the names in your situation - but tradition in relation to mr and mrs xyz comes from the place where people were married, those couple dynamics have changed especially in the last 50 years.
However sexism is alive against men too:
Men's names on birth certificates
Recent posts in women's pension ages
Mums save at Iceland adverts
The name of this forum : Mumsnet enough men use the forum for it now to be parentsnet surelt?
Mothercare. The name bugs me every time I go in there
Mother and child parking in some places
Ladies night in freemasonry (recent post on MN)
Ladies and gentlemen, boys and girls - the saying..... perhaps we should change that!
I could carry on...
And as for dear sirs (as mentioned above), it's the formal way of writing openly to 2 or more professional people when unsure which one will deal with the correspondence
I 100% support equality - however why ladies don't regularly support the equal rights of men annoys me
Mother and toddler groups are my main gripe - where is the MN post saying boycott them until it becomes parent and toddler?!?!
Or shall we now pick on the word 'boycott' as being Ild fashioned and sexist too? :-)
I'll crawl back under my rock now