I've tried to help you see how UBI proponents have not only anticipated your line of reasoning, but have long finished figuring out things like impact on business. Quoting from the summary of the Roosevelt Institute's study:
> When paying for the policy by increasing taxes on households, the Levy model forecasts no effect on the economy. In effect, it gives to households with one hand what it is takes away with the other.
> However, when the model is adapted to include distributional effects, the economy grows, even in the tax-financed scenarios. This occurs because the distributional model incorporates the idea that an extra dollar in the hands of lower income households leads to higher spending. In other words, the households that pay more in taxes than they receive in cash assistance have a low propensity to consume, and those that receive more in assistance than they pay in taxes have a high propensity to consume.
As long as you are predisposed to look down on so many people for supposed moral failings, and look at people as "couch potatoes", you are going to have a blind spot where you don't recognize how essential cheap labor is to our way of life.