Thanks for spelling out your point, and yes, I don't agree with it. Being in prison is the punishment. People don't lose their humanity because they are in prison, and they don't need to or deserve to be additionally punished by forcing them to eat meals that go against their religious or ethical convictions.
What's more, people in prison usually don't stay there forever. The idea that it doesn't matter how we treat people in prison because "it's not a hotel" is not conducive to reintegration and is harmful to everyone, including you.