Self employed

I do understand that a home office rent is not deductible in the case of a loss.  My client did not have a loss however.

His gross income for his business, and the instructions do specifically say gross income, was around 48K.

10% of his revenue was attributable to the home office, the other 90% was due to on-site product   demonstrations.  Those demonstrations actually represented an even higher proportion of the total expenses.

My issue with the guidelines is that the portion of income attributable to the home office must exceed the entirety of expenses for his business.  That is a glaring disconnect to me. I could understand how the home office income should exceed the expenses related to the home office, but why must they exceed the entirety of the business expenses.