Why won't my husband look for a job?

My husband is 36 years old and has only held one job in his entire life for more than one year (and he held it for about three years). He quit his last job to start his own business, which he has been doing for over a year now. The most he has made in one month is $800 before deducting any expenses. Luckily I have a decent full-time job, but we are barely scraping by. But he will not look for a regular job! WHY??? I'm so frustrated and so resentful!