People believe in gods, and nobody bats an eye.
People believe in aliens, and nobody bats an eye.
People believe in a conscious AI, and everybody loses their shit?
People have attributed intelligence to imaginary friends since the birth of time, let them have fun in their make-believe world.
Computers rule our world, their existence is not a question so people's reaction and interest is understandable. There are very real fears that AI could mass destroy jobs before we can fix our social systems and benefits, like universal basic income.
Many of us grew up with movies like Wargames and Terminator, so it's easy to see how people make the leap from 'is this machine sentient' to 'machines will take over the world'. That said, it's still a knee jerk reaction at this point - we don't have sentient AI, so don't have to worry about it eventually wiping out humankind.
People who believe in conscious/sentient AI—and, more specifically, believe that some of our current AIs have these properties—consequently believe they have reason to call for changes to how we as a society treat AIs. Those changes are likely to vary—some may call for restricting or banning them entirely, while others call for giving them rights, depending on just what stories about AI they've bought into—but whatever their overall direction, if taken seriously, they would be likely to severely hamper our ability to continue to progress technologically using machine learning.