Workmen could be excused on the grounds that if they had been marvellous at spelling they probably wouldn't be all that good using their hands and tools, so would not have become workmen.
Secretaries, receptionists or teachers should both be able to spell and read through letters etc. before sending them.
A friend of mine received a letter from the hospital's gynaecological surgical dept. scheduling the date for her hysterectomy.
It was, suprisingly enough, addressed to Mr. NN!
Now in English that might have been a clerical error, but in Danish, which was the language used there is a longer way between Hr. NN and Fr, NN on any keyboard, and her given name was definitely a woman's name.
And honestly, how many men have ever had their uterus removed?