Except that SQLite is a library that can be embedded into any program.
Yes, there's also a binary command line interface to interface with a db file, but that's not what SQLite mainly is.
Yes, there's also a binary command line interface to interface with a db file, but that's not what SQLite mainly is.
It's also worth noting that you also have the option of purchasing a license for $6000. I'd imagine it's mostly companies that are likely to have concerns over licensing issues, and for most companies that price should be completely affordable. Especially when you consider the project's superb quality level and extensive test suite.