Our company has an ASP.NET application for customer information database. The application started small but has grown without proper design. Now a new version of the app sho
Short answer: No.
Long answer: Is there any collaboration? Supporting documentation for the data? Workflow? If no, then there really isn't any reason to host it through SharePoint - you won't be gaining much.
Additionally, keep in mind that the SharePoint lists may look like tables, but they aren't - there is no relational aspects of the lists - no joining, no cascading updates/deletes, etc. This may be a problem if data reporting is a big part of your app.
You can store the data externally and have it appear as read-only lists in SharePoint, but you're still jumping through a lot of hoops if you're not using any of the other SharePoint features.