I think this is mostly a US thing. Why use yearly salary? You're not paid once a year, are you? Most likely once a month. Referencing monthly salary makes much more sense.
"I'm making 50k". Great, now I have to guess - dollars? Monthly? Yearly? If yearly then what's the monthly paycheck? Net? Gross?
Mortgages neither. Mine is accelerated bi-weekly, meaning I pay essentially 13 months a year... It shaves a wooping 3 and a half years on my 25 years!