The ADA needs to be changed. If the act is really about disabled access, and nothing else, then...
1) All complaints must first be processed through the local building compliance department,
2) IF deemed legit, upon notification, the building/business owner has a reasonable time, 6-12 months depending on the magnitude of the upgrades, to bring the premises up to code,
3) Once upgrades are complete and approved by said local building compliance department, the complaint is permanently dismissed,
4) If the building/business owner does not bring the property up to code, then and only then, would the plaintiff be allowed to sue for damages.