Why use Access DB ?

It's common to use Access for small, noncritical tasks even if a larger, more robust system is available. Occasionally, an Access database grows beyond its original purpose. After a year or two of use, an Access database can become vital to the organization. It doesn't happen often, but it does happen. At this point, the IT professional faces a challenge -- revamp the Access database or upgrade, and both require a lot of work.

• Poor security; Access security simply isn't as robust as you might need. You can password-protect and even encrypt data, but Access doesn't offer the same level of security as SQL Server
• Access is hard to deploy; there are several versions, upgrades can also be a nuisance (ex global upgrade for Microsoft Office )
• File-server application; , Access is a file-server application and not a client-server application. That means that Access does all its processing on one server. Client-server applications process on both sides of the network. While that arrangement is more flexible, it also comes with overhead.
• Money; Access applications are cheaper to build and maintain than the more sophisticated productions of SQL Server and Oracle
• Reliability, integrity and availability; corruption is one area where Access is weak , Regardless of the source, corruption is a real problem; the possibility to have concurrent users is not possible. Backup and Restore of the data is not consistent like SQL/Oracle. 
• Access isn’t a professional database
• Supporting issue; while the database might get the job done, it's usually inefficient and difficult to maintain. Invariably, these innovative folks end up calling IT to help resolve a bug or add a new feature. Some IT professionals simply refuse to help, and understandably so. That kind of problem-solving and debugging is difficult and time-consuming. Access uses Visual Basic for Applications (VBA) as its development language. Technically, VBA is a subset of Visual Basic (VB)