I do not agree about Access with you. It is excellent for first-time, inexperienced users, for casual access to data. I am not aware of any other DB interface (for the price) with so easy to use visual query builder, or "query by form". You cannot beat easiness of building SQL table JOINs visually.
Sure enough, when you need to do more serious development, you are seduced to MS concepts, but can avoid it by using DBI, ODBC and perl. With DBI, perl, and little thinking , I may not care what database I am connected into.
Access (== MS Jet database engine) has record locking and transactions as real databases have, which I doubt about text files... ;)
And sure enough, if you do not need PC, and free *NIXish system is acceptable for users, just go ahead.
Installed OS is not a "religious issue" for me. User needs to be comfortable with the OS selected, and luckily enough I can port my perl on almost any system (there was discussion about porting Perl to Palm PDA- can you believe that?).
Obviously, if users like to try to equip 50 PCs with Linux and StarOffice, excellent - Micro$oft is rich enough. If I may not care about transactions - so mysql is enough, it's fine. I did not use Postgress DB, so I cannot recomment id. After many years using database PROGRESS and it's clever 4GL language, I am back to plain stupid SQL on ORACLE, and only perl makes this experience bearable... ;)
And I am sure Access is more than minesweeper: Access can do transactions and rollback, but minesweeper cannot. :)
Update: Full disclosure: I am using Access/ODBC connection to ORACLE database to check how my CGI scripts are working. I found it easier - because I know it already...:)
To make errors is human. But to make million errors per second, you need a computer.