This would be good for startup owners who no longer have to worry about where their next meal is coming from.
I understand your intent but that fundamentally misunderstands the nature of startups and funding. Nobody is going to be able to create a startup they otherwise wouldn't have because they are getting a $10K UBI instead of working at a job. Start-ups cost money - usually a lot of it - because they need resources and people who require actual money to get paid for. (If your startup employees were going to work for less than $10K/year or UBI income anyway, then they didn't need this incentive.) Most software startups generally require - depending on scope - anywhere from $100K to $250K just to get started in the first year, and that is far beyond what UBI can provide. If your startup is in hardware, expect your first year to require an order of magnitude more startup funding.
The point being that UBI does nothing to encourage new startups. Entrepreneurs need capital - which (at least for non-billionaires, who are only a tiny percentage of investors in startups) arguably might be lessened if potential investors were paying the increased taxes necessary for the government to dole out UBIs.