How do you filter out bad-fit signups without hurting growth?

It feels great seeing high signup numbers every week, but watching 60% of a specific user segment churn after month one is demoralizing.

We realized these users were signing up with expectations our tool was never built to solve. They churn not because the product is bad, but because they were the wrong audience from day one and their feedback was polluting our roadmap.

How do you implement qualification gates or repositioning early in the funnel without turning away good prospects?