That's not any different than what we already have, though. There are numerous entitlements (food stamps, Medicaid, WIC, public housing, etc.) that already do exactly the same thing.
By that token UBI is also subsidizing companies employing low wage earners, because it allows people to take low-paid jobs that they otherwise wouldn't since they wouldn't be able to survive on them without UBI. Also, marginal utility of money means that $15K going to someone who is well-compensated isn't that meaningful, but it means a lot to someone working a part-time minimum wage job, so the latter is compensated more (thus, subsidy).
By that token UBI is also subsidizing companies employing low wage earners, because it allows people to take low-paid jobs that they otherwise wouldn't since they wouldn't be able to survive on them without UBI. Also, marginal utility of money means that $15K going to someone who is well-compensated isn't that meaningful, but it means a lot to someone working a part-time minimum wage job, so the latter is compensated more (thus, subsidy).