A belief that it can't happen to you, which, chances are, is correct. They then regret not having insurance when the odds turn against them. Belief that business operations are covered by existing non-business policies. The basic misconception of home business owners. Special insurance policies cover every possible related occurrence.
Policies only cover what is in the fine print.
Risk is too small to justify the cost for insurance. Insurance costs, however, are based upon risk characteristics. Costs beyond budget. If you can't afford to replace your business out of pocket, then insurance must be part of that budget. Belief the costs are too much.