Touristic Visa

Is it really necessary having an invitation letter to get a touristic L?? I'm an Italian woman (expat in Doha) and I organized a 4-day-long travel to Beijing to accompany my husband who will be there for a work conference with Qatar Fondation. I have been going to China embassy already 5 times and the desk clerks always required me all kind of document which I carefully got.
Today I was told (for the first time!) I must have an invitation letter by a Chinese to get a touristic L even if I don't know any Chinese person!
How possible is it? I traveled a lot with my husband and I never had these kind of problems before...
Do anyone help me or give me an advice?