Because in America, that statement is so heretical and antithetical to what the average American thinks America is, that most people probably wouldn't even be mad at you for saying it: They'd think you were legitimately unwell/insane.
It's on the same level as saying "I hate liberals and am not conservative".
I would talk about how what's most important is workers rights and wages. All sorts of businesses are capable of taking advantage of their employees and that's what matters to you. Then explain the unique situations that make small businesses vulnerable, like them being less likely to held accountable for labor violations. Don't frame it as small businesses suck, just say that workers matter more.