Well, since your district's public school... is rated very low, that is not an ideal school.
Some public schools, are very good and rated very highly. Like my kids' public school. Many people, try to get into that school. Because of its top reputation.
But again, your local area public school, is rated low.
No school is 'perfect'.... but quality does differ.
You said you both CAN afford the private school.
I think, your Husband's response is a bit about his own... insecurity and about where he went to school. Long ago. He is responding out of 'habit' and how his schooling was. Some habits like that... are engrained in people. They don't thus, look at other options.
Now finances/tuition is of course a concern of anyone. But you said you both can afford it.
Now.
Are your jobs, secure? Since that is the stream of income to pay for school etc.
It is not about your way or your husband's way... it is about what is best, for your child and per the environment of the school... in addition to its curriculum and rating etc.
You and Hubby, still need to discuss this.
Perhaps, showing him your responses... unless he will get angry about your post. Since it is about him.